Update major version check

.github/workflows/major-version-check.yml

@@ -16,6 +16,8 @@ jobs:
     if: |
       !contains(github.event.pull_request.labels.*.name, '🤖Skip Major Check')
     runs-on: ubuntu-latest
+    env:
+      HEAD_REF: ${{ github.head_ref }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v3
@@ -24,11 +26,11 @@ jobs:
         run: git fetch --all
 
       - name: Checkout the feature branch
-        run: git checkout ${{ github.head_ref }} --
+        run: git checkout "$HEAD_REF" --
 
       - name: Check major versions in changeset entries
         run: |
-          commits="origin/${{ github.base_ref }}...origin/${{ github.head_ref }}"
+          commits="origin/$("$HEAD_REF")...origin/$("$HEAD_REF")"
           changeset_files=$(git diff --name-only --diff-filter=d "$commits" -- ".changeset/*.md")
 
           if [[ -z "$changeset_files" ]]; then