fix(close bug report action): target branch name has been renamed stable

[gauthierpetetin]

Description

The Github action that was automatically closing release bug report when release branch was merged stopped working after release 7.37.0, because the name of the target branch for the release PR has changed: the release PR now gets merged into stable.

This is a fix for the Github action.

Related issues

Fixes: None

Manual testing steps

1. Merge a release PR such as 7.41.0
2. Close bug report Github action shall be executed successfully, and 7.41.0 shall appear in this list

(we'll only be able to test this for next release though)

Screenshots/Recordings

• None

Pre-merge author checklist

• I’ve followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I’ve included tests if applicable
• I’ve documented my code using JSDoc format if applicable
• I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud