👷 Skip check-staging-merge for PRs targeting next major version branch

[thomas-lebeau]

Motivation

The check-staging-merge CI job verifies that a feature branch can be cleanly merged into the current staging branch. This check is only relevant for PRs targeting main (which go through the staging process). PRs targeting the v7 (next major) branch don't use staging, so this check is irrelevant and should be skipped.

Changes

• Fetch PR info from GitHub API via fetchPR() to determine the target branch
• If the PR targets NEXT_MAJOR_BRANCH (e.g. v7), exit early with a success message
• Otherwise, continue with the existing staging merge check logic unchanged
• Handles edge cases: no PR exists (continues check), NEXT_MAJOR_BRANCH not set (continues check)

Test instructions

• PR targeting v7 → staging merge check is skipped
• PR targeting main → staging merge check runs as before
• Branch with no PR → staging merge check runs as before

Checklist

• Tested locally
• Tested on staging
• Added unit tests for this change.
• Added e2e/integration tests for this change.
• Updated documentation and/or relevant AGENTS.md file