Fix GitHub Actions auth step to skip when running from forks

[sagarswamirao]

Problem

The google-github-actions/auth@v2 action fails when secrets aren't available, which happens for workflows triggered from forks (including Dependabot). The error message is:

Error: google-github-actions/auth failed with: the GitHub Action workflow must specify exactly one of "workload_identity_provider" or "credentials_json"! If you are specifying input values via GitHub secrets, ensure the secret is being injected into the environment. By default, secrets are not passed to workflows triggered from forks, including Dependabot.

Solution

Add a condition to skip the auth step when running from a fork. The condition checks if:

• It's not a pull request (i.e., it's a push), OR
• It's a pull request from the same repository (not a fork)

This prevents the workflow from failing when secrets aren't available, while still running authentication for legitimate runs from the main repository.

Changes

• Added if condition to GCloud auth step to skip when running from forks