Updates dev guide to inform the workflow approval step (opensearch-project#3062)

* Updates dev guide to inform the workflow approval step

Signed-off-by: Brian Flores <iflorbri@amazon.com>

* Adjusted reason for workflow approval

Signed-off-by: Brian Flores <iflorbri@amazon.com>

---------

Signed-off-by: Brian Flores <iflorbri@amazon.com>

Author: brianf-aws

DEVELOPER_GUIDE.md

@@ -11,6 +11,7 @@ This guide applies to the development within the ML-Commons project
     - [Build](#Build)
       - [Building from the command line](#Building-from-the-command-line)
       - [Debugging](#Debugging)
+- [GitHub CI/CD workflow Approval](#github-cicd-workflow-approval)
 - [More documentation](#More-docs)
 - [Code guidelines](#code-guidelines)
 
@@ -96,7 +97,7 @@ This package uses the [Gradle](https://docs.gradle.org/current/userguide/usergui
 7. `./gradlew integTest -Dtests.rest.cluster=localhost:9200 -Dtests.cluster=localhost:9200 -Dtests.clustername="docker-cluster" -Dhttps=true -Duser=admin -Dpassword=admin` launches integration tests against a local cluster and run tests with security. Detail steps: (1)download OpenSearch tarball to local and install by running `opensearch-tar-install.sh`; (2)build ML plugin zip with your change and install ML plugin zip; (3)restart local test cluster; (4) run this gradle command to test.
 8. `./gradlew spotlessApply` formats code. And/or import formatting rules in `.eclipseformat.xml` with IDE.
 
-When launching a cluster using one of the above commands logs are placed in `/build/cluster/run node0/opensearch-<version>/logs`. Though the logs are teed to the console, in practices it's best to check the actual log file.
+When launching a cluster using one of the above commands logs are placed in `/build/cluster/run node0/opensearch-<version>/logs`. Though the logs are tied to the console, in practices it's best to check the actual log file.
 
 #### Debugging
 
@@ -118,6 +119,13 @@ To debug code running in an integ test (which exercises the server from a separa
 
 The test runner JVM will start suspended and wait for a debugger to attach to `localhost:5005` before running the tests.
 
+## GitHub CI/CD workflow Approval
+Effective October 2, 2024, maintainer approval will be required to run GitHub CI/CD workflow actions when pushing a pull request (PR).
+
+This change is being implemented as part of our enhanced security measures. We appreciate your patience and cooperation.
+
+For a list of current maintainers, please refer to [MAINTAINERS.md](https://github.com/opensearch-project/ml-commons/blob/main/MAINTAINERS.md).
+
 ## More docs
 
 1. [Model serving framework](https://opensearch.org/docs/latest/ml-commons-plugin/model-serving-framework/)