fix(ci): generate translation checkouts with sha instead of branch

.github/workflows/generate_translations.yml

@@ -23,7 +23,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           fetch-depth: 50
-          ref: ${{ github.head_ref }}
+          ref: ${{ github.sha }}
 
       - name: Set up Python
         uses: actions/setup-python@v5