removed task for installing git-core

the playbook in this repo is meant to run from an EE using automation
controller when bootstrapping product demos, so git should already be
available given the dependency between ansible-core and git-core

install_product_demos.yml

@@ -4,16 +4,11 @@
 
   vars:
     controller_postinstall_repo_url: https://github.com/ansible/product-demos-postinstall.git
-    controller_poistinstall_repo_ref: main
+    controller_postinstall_repo_ref: main
     controller_postinstall_dir: '{{ playbook_dir }}/product-demos-postinstall'
     controller_postinstall_ignore_files: []
 
   tasks:
-    - name: Ensure the git binary is available
-      ansible.builtin.package:
-        name: git-core
-      become: true
-
     - name: Check out product-demos-postinstall repo
       ansible.builtin.git:
         repo: '{{ controller_postinstall_repo_url }}'