Drop Python 3.8 support (#11529)

* Drop Python 3.8 support

Dropping `3.8` as announced here:
https://github.blog/changelog/2025-02-05-dependabot-no-longer-supports-python-3-8/

* Update poetry test files

python/Dockerfile

@@ -5,7 +5,6 @@ ARG PY_3_12=3.12.9
 ARG PY_3_11=3.11.11
 ARG PY_3_10=3.10.16
 ARG PY_3_9=3.9.21
-ARG PY_3_8=3.8.20
 ARG PYENV_VERSION=v2.5.2
 
 FROM ghcr.io/dependabot/dependabot-updater-core AS python-core
@@ -14,7 +13,6 @@ ARG PY_3_12
 ARG PY_3_11
 ARG PY_3_10
 ARG PY_3_9
-ARG PY_3_8
 ARG PYENV_VERSION
 USER root
 
@@ -36,24 +34,6 @@ RUN git -c advice.detachedHead=false clone https://github.com/pyenv/pyenv.git --
 # Although it is convenient when debugging to be able to quickly flip through environments.
 RUN mkdir "${PYENV_ROOT}/versions"
 
-## 3.8
-# Docker doesn't support parametrizing `COPY --from:python:$PY_1_23-bookworm`, so work around it using an alias.
-# TODO: If upstream adds support for Ubuntu, use that instead of Debian as the base suffix: https://github.com/docker-library/python/pull/791
-FROM docker.io/library/python:$PY_3_8-bookworm AS upstream-python-3.8
-FROM python-core AS python-3.8
-ARG PYTHON_INSTALL_LOCATION="$PYENV_ROOT/versions/$PY_3_8"
-COPY --from=upstream-python-3.8 --chown=dependabot:dependabot /usr/local/bin $PYTHON_INSTALL_LOCATION/bin
-COPY --from=upstream-python-3.8 --chown=dependabot:dependabot /usr/local/include $PYTHON_INSTALL_LOCATION/include
-COPY --from=upstream-python-3.8 --chown=dependabot:dependabot /usr/local/lib $PYTHON_INSTALL_LOCATION/lib
-# `pip` and other scripts need their shebangs rewritten for the new location
-RUN find $PYTHON_INSTALL_LOCATION/bin -type f -exec sed -i "1s|^#!/usr/local/bin/python|#!$PYTHON_INSTALL_LOCATION/bin/python|" {} +
-# Ensure pyenv works and it's the python version we expect
-RUN PYENV_VERSION=$PY_3_8 pyenv exec python --version | grep "Python $PY_3_8" || exit 1
-RUN bash /opt/python/helpers/build $PY_3_8
-# This python environment occupies ~0.5 GB and gets used for a fraction of jobs, so store it compressed.
-RUN cd $PYENV_ROOT/versions \
-  && tar -acf $PY_3_8.tar.zst $PY_3_8
-
 ## 3.9
 # Docker doesn't support parametrizing `COPY --from:python:$PY_1_23-bookworm`, so work around it using an alias.
 # TODO: If upstream adds support for Ubuntu, use that instead of Debian as the base suffix: https://github.com/docker-library/python/pull/791
@@ -168,7 +148,6 @@ COPY --chown=dependabot:dependabot common $DEPENDABOT_HOME/common
 COPY --chown=dependabot:dependabot updater $DEPENDABOT_HOME/dependabot-updater
 
 # Running these steps last means that if the builds in the concurrent stages take longer it doesn't block the pipeline until the end.
-COPY --from=python-3.8 $PYENV_ROOT/versions/$PY_3_8.tar.zst $PYENV_ROOT/versions/$PY_3_8.tar.zst
 COPY --from=python-3.9 $PYENV_ROOT/versions/$PY_3_9.tar.zst $PYENV_ROOT/versions/$PY_3_9.tar.zst
 COPY --from=python-3.10 $PYENV_ROOT/versions/$PY_3_10.tar.zst $PYENV_ROOT/versions/$PY_3_10.tar.zst
 COPY --from=python-3.11 $PYENV_ROOT/versions/$PY_3_11.tar.zst $PYENV_ROOT/versions/$PY_3_11.tar.zst

python/helpers/requirements.txt

@@ -1,8 +1,6 @@
 pip==24.0
 pip-tools==7.4.1
 flake8==7.1.0
-# TODO: Drop the conditions and use the latest version once we drop support for Python 3.8.
-hashin==1.0.2; python_version < '3.9'
 hashin==1.0.3; python_version >= '3.9'
 pipenv==2024.0.2
 plette==2.1.0

python/lib/dependabot/python/language_version_manager.rb

@@ -16,7 +16,6 @@ class LanguageVersionManager
         3.11.11
         3.10.16
         3.9.21
-        3.8.20
       ).freeze
 
       sig { params(python_requirement_parser: T.untyped).void }

python/spec/dependabot/python/file_updater/poetry_file_updater_spec.rb

@@ -126,9 +126,9 @@
     end
 
     context "with the oldest python version currently supported by Dependabot" do
-      let(:python_version) { "3.8.17" }
-      let(:pyproject_fixture_name) { "python_38.toml" }
-      let(:lockfile_fixture_name) { "python_38.lock" }
+      let(:python_version) { "3.9.21" }
+      let(:pyproject_fixture_name) { "python_39.toml" }
+      let(:lockfile_fixture_name) { "python_39.lock" }
       let(:dependency) do
         Dependabot::Dependency.new(
           name: "django",

python/spec/dependabot/python/update_checker/pip_version_resolver_spec.rb

@@ -84,18 +84,18 @@
       it { is_expected.to eq(Gem::Version.new("3.2.4")) }
 
       context "when the version is set to the oldest version of python supported by Dependabot" do
-        let(:python_version_content) { "3.8.0\n" }
+        let(:python_version_content) { "3.9.0\n" }
 
         it { is_expected.to eq(Gem::Version.new("3.2.4")) }
       end
 
       context "when the version is set to a python version no longer supported by Dependabot" do
-        let(:python_version_content) { "3.7.0\n" }
+        let(:python_version_content) { "3.8.0\n" }
 
         it "raises a helpful error" do
           expect { latest_resolvable_version }.to raise_error(Dependabot::ToolVersionNotSupported) do |err|
             expect(err.message).to start_with(
-              "Dependabot detected the following Python requirement for your project: '3.7.0'."
+              "Dependabot detected the following Python requirement for your project: '3.8.0'."
             )
           end
         end
@@ -131,18 +131,18 @@
       it { is_expected.to eq(Gem::Version.new("2.1.1")) }
 
       context "when the version is set to the oldest version of python supported by Dependabot" do
-        let(:python_version_content) { "3.8.0\n" }
+        let(:python_version_content) { "3.9.0\n" }
 
         it { is_expected.to eq(Gem::Version.new("2.1.1")) }
       end
 
       context "when version is set to a python version no longer supported by Dependabot" do
-        let(:python_version_content) { "3.7.0\n" }
+        let(:python_version_content) { "3.8.0\n" }
 
         it "raises a helpful error" do
           expect { lowest_resolvable_security_fix_version }.to raise_error(Dependabot::ToolVersionNotSupported) do |err|
             expect(err.message).to start_with(
-              "Dependabot detected the following Python requirement for your project: '3.7.0'."
+              "Dependabot detected the following Python requirement for your project: '3.8.0'."
             )
           end
         end

python/spec/dependabot/python/update_checker_spec.rb

@@ -225,18 +225,18 @@
         it { is_expected.to eq(Gem::Version.new("3.2.4")) }
 
         context "when the version is set to the oldest version of python supported by Dependabot" do
-          let(:python_version_content) { "3.8.0\n" }
+          let(:python_version_content) { "3.9.0\n" }
 
           it { is_expected.to eq(Gem::Version.new("3.2.4")) }
         end
 
         context "when the version is set to a python version no longer supported by Dependabot" do
-          let(:python_version_content) { "3.7.0\n" }
+          let(:python_version_content) { "3.8.0\n" }
 
           it "raises a helpful error" do
             expect { latest_resolvable_version }.to raise_error(Dependabot::ToolVersionNotSupported) do |err|
               expect(err.message).to start_with(
-                "Dependabot detected the following Python requirement for your project: '3.7.0'."
+                "Dependabot detected the following Python requirement for your project: '3.8.0'."
               )
             end
           end