Construct target branch name in checks step

Author: mbg

.github/workflows/update-proxy-release.yml

@@ -22,13 +22,16 @@ jobs:
       RELEASE_TAG: ${{ inputs.tag || 'codeql-bundle-v2.22.0' }}
     steps:
       - name: Check release tag format
+        id: checks
         shell: bash
         run: |
           if ! [[ $RELEASE_TAG =~ "^codeql-bundle-v[0-9]+\.[0-9]+\.[0-9]+$" ]]; then
             echo "Invalid release tag: expected a CodeQL bundle tag in the 'codeql-bundle-vM.N.P' format."
             exit 1
           fi
 
+          echo "target_branch=dependency-proxy/$RELEASE_TAG" >> $GITHUB_OUTPUT
+
       - name: Check that the release exists
         shell: bash
         env:
@@ -61,7 +64,6 @@ jobs:
       - name: Push changes and open PR
         shell: bash
         env:
-          BRANCH: "dependency-proxy/${{ env.RELEASE_TAG }}"
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
         run: |
           set -exu
@@ -77,16 +79,16 @@ jobs:
           EOF
           )
 
-          git checkout -b "$BRANCH"
+          git checkout -b "${{ steps.checks.outputs.target_branch }}"
 
           npm run build
           git add ./src/start-proxy-action.ts
           git add ./lib
           git commit -m "$pr_title"
 
-          git push origin "$BRANCH"
+          git push origin "${{ steps.checks.outputs.target_branch }}"
           gh pr create \
-            --head "$BRANCH" \
+            --head "${{ steps.checks.outputs.target_branch }}" \
             --base "main" \
             --title "${pr_title}" \
             --body "${pr_body}" \