Description

Fixes #6912

• Adds a comment to the KubernetesPodOperator explaining that pod affinity isn't supported in Composer 2
• Adds a comment and error handling to the get_client_id utility regarding usage with Composer 2
• Adds a comment to the trigger_dag cloud function regarding usage with Composer 2 (users will likely use get_client_id before using the trigger_dag function and will get a more detailed error message there. Updating this script will come in a later PR)
• Adds 3.10 exemption to noxfile config - Composer w/ Airflow 2 (both composer 1 and composer 2) are Python 3.8 only as of now

cc @rafalbiegacz @pavel-salnikov

Note: It's a good idea to open an issue first for discussion.

Checklist

• I have followed Sample Guidelines from AUTHORING_GUIDE.MD
• README is updated to include all relevant information
• Tests pass: nox -s py-3.6 (see Test Environment Setup)
• Lint pass: nox -s lint (see Test Environment Setup)
• These samples need a new API enabled in testing projects to pass (let us know which ones)
• These samples need a new/updated env vars in testing projects set to pass (let us know which ones)
• Please merge this PR for me once it is approved.
• This sample adds a new sample directory, and I updated the CODEOWNERS file with the codeowners for this sample