Merge pull request #4010 from github/mbg/ts/update-release-branch

Convert `update-release-branch.py` to TypeScript

Author: mbg

.github/actions/release-branches/action.yml

@@ -22,7 +22,6 @@ runs:
         MAJOR_VERSION: ${{ inputs.major_version }}
         LATEST_TAG: ${{ inputs.latest_tag }}
       run: |
-        npm ci
         npx tsx ./pr-checks/release-branches.ts \
             --major-version "$MAJOR_VERSION" \
             --latest-tag "$LATEST_TAG"

.github/actions/release-initialise/action.yml

@@ -21,6 +21,10 @@ runs:
         node-version: 24
         cache: 'npm'
 
+    - name: Install JavaScript dependencies
+      shell: bash
+      run: npm ci
+
     - name: Set up Python
       uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       with: