Use composite action for determining next tag

.github/workflows/tag.yml

@@ -23,64 +23,16 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ github.ref == 'refs/heads/main' }}
 
-    # Expose step outputs as job outputs
-    outputs:
-      new_tag: ${{ steps.determine_next_tag.outputs.new_tag }}
-
     steps:
-      - uses: actions/github-script@v6
-        id: get_pr_data
-        with:
-          script: |
-            return (
-              await github.rest.repos.listPullRequestsAssociatedWithCommit({
-                commit_sha: context.sha,
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-              })
-            ).data[0];
-
       - uses: actions/checkout@v4
       - uses: fregante/setup-git-user@v2
 
-      - name: Debug
-        run: |
-          echo ${{ github.event_name }}
-          echo ${{ github.ref }}
-          echo ${{ github.event.pull_request.head.ref }}
-          echo ${{ github.event.pull_request.base.ref }}
-          echo ${{ github.event }}
-
-      - name: Dump GitHub context
-        env:
-          GITHUB_CONTEXT: ${{ toJson(github) }}
-        run: echo "$GITHUB_CONTEXT"
-      - name: Dump job context
-        env:
-          JOB_CONTEXT: ${{ toJson(job) }}
-        run: echo "$JOB_CONTEXT"
-      - name: Dump steps context
-        env:
-          STEPS_CONTEXT: ${{ toJson(steps) }}
-        run: echo "$STEPS_CONTEXT"
-
       - name: Determine new tag version
         id: determine_next_tag
-        # User controlled input needs to be santitised beforehand e.g., by adding an
-        # intermediate env var to prevent the workflow being exposed to a critical
-        # command injection attack
-        env:
-          PR_BODY: "${{ fromJson(steps.get_pr_data.outputs.result).body }}"
-          PR_NUMBER: "${{ fromJson(steps.get_pr_data.outputs.result).number }}"
-        run: |
-          echo "Attempting to auto-tag merge commit"
-          script_output=$("${{ github.action_path }}/.github/auto-tag.sh" "${PR_BODY}" "${PR_NUMBER}")
-          if $? != 0; then
-            exit 1
-          fi
-          new_tag=$(echo "${script_output}" | tail -n 1)
-          echo "New tag: ${new_tag}"
-          echo "new_tag=${new_tag}"  >> "$GITHUB_OUTPUT"
+        uses: climatepolicyradar/get-next-tag-from-pr-body@main
+
+      - name: Echo next tag
+        run: echo ${{ steps.determine_next_tag.outputs.new_tag }}
 
   semver:
     needs: git