ci(vuln): remediate GHA script injection

Merge pull request #29 from rudderlabs/fix/sec-93-remediate-gha-injection

Author: 1abhishekpandey

.github/workflows/publish-new-release.yml

@@ -30,9 +30,10 @@ jobs:
 
       - name: Extract version from branch name (for release branches)
         id: extract-version
+        env:
+          BRANCH_NAME: ${{ github.event.pull_request.head.ref }}
         run: |
-          BRANCH_NAME="${{ github.event.pull_request.head.ref }}"
-          VERSION=${BRANCH_NAME#release/}
+          VERSION="${BRANCH_NAME#release/}"
           echo "release_version=$VERSION" >> $GITHUB_OUTPUT
 
       - name: Checkout source branch