ToggleLockBranch: Disable Auto-Merge on existing PRs #75
Description
When a branch is locked/unlocked, the action should:
- iterate all PRs targeting that branch
- disable AutoMerge, if it is enabled. For locking AND unlocking.
https://docs.github.com/en/graphql/reference/mutations#disablepullrequestautomerge
For testing: Validate what will happen if the repo doesn't have Auto-Merge enabled.
In case master is frozen (for example due to release), we don't want any PR to accidentally be merged faster than a version bump.
The disabling should happen
- when locking the branch, to clearly indicate that PRs will not be merged after
- when unlocking the branch, to prevent unexpected auto-merge for PRs that were configured for auto-merge in the meantime