Revert "Run mapping updates against the selected workflow branch"

.github/workflows/update-mappings.yml

@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
 
     env:
-      AUTOMATION_BRANCH: dev/automated-mapping-update-${{ github.ref_name }}
+      AUTOMATION_BRANCH: dev/automated-mapping-update
       NTE_ASSETS_REF: ${{ inputs.source_ref }}
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -32,7 +32,7 @@ jobs:
         uses: actions/checkout@v5
         with:
           fetch-depth: 0
-          ref: ${{ github.ref_name }}
+          ref: ${{ github.event.repository.default_branch }}
 
       - name: Get Python
         uses: actions/setup-python@v6
@@ -91,7 +91,7 @@ jobs:
         if: steps.changes.outputs.changed == 'true'
         shell: bash
         env:
-          BASE_BRANCH: ${{ github.ref_name }}
+          BASE_BRANCH: ${{ github.event.repository.default_branch }}
           RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
         run: |
           python - <<'PY'