chore: remove test branch from analytics-metadata-updater workflow (#33703)

### Description of changes
Remove test branch for triggering the workflow.

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: paulhcsun

.github/workflows/analytics-metadata-updater.yml

@@ -3,7 +3,6 @@ on:
   workflow_dispatch:
   pull_request:
     branches:
-      - yuanhaoz/metadata_workflow # TODO, remove this
       - v2-release
 
 jobs: