fix(updater): Trigger CI for new PRs without changelog updates

New updater PRs can end with no branch update after creation when
changelog entries are disabled. Amend and push the created PR commit in
that case so GitHub emits a pull_request synchronize event.

Fixes: #164
Co-Authored-By: OpenAI Codex <noreply@openai.com>

Author: jpnurmi

updater/action.yml

@@ -462,3 +462,32 @@ runs:
           Auto-generated by a [dependency updater](https://github.com/getsentry/github-workflows/blob/main/updater/action.yml).
           ${{ env.TARGET_CHANGELOG }}
         labels: dependencies
+
+    - name: Trigger PR workflows
+      if: ${{ ( steps.create-pr.outputs.pull-request-operation == 'created' ) && ( steps.update.outputs.pull-request-head-sha == '' || steps.update.outputs.pull-request-head-sha == steps.create-pr.outputs.pull-request-head-sha ) }}
+      shell: bash
+      working-directory: caller-repo
+      env:
+        PR_BRANCH: ${{ steps.root.outputs.prBranch }}
+        PR_HEAD_SHA: ${{ steps.create-pr.outputs.pull-request-head-sha }}
+        API_TOKEN: ${{ inputs.api-token }}
+        SSH_KEY: ${{ inputs.ssh-key }}
+      run: |
+        git fetch origin "$PR_BRANCH"
+        git checkout --force -B "$PR_BRANCH" "origin/$PR_BRANCH"
+
+        current_head=$(git rev-parse HEAD)
+        if [ "$current_head" != "$PR_HEAD_SHA" ]; then
+          echo "::notice::PR branch changed from $PR_HEAD_SHA to $current_head; skipping synthetic CI trigger."
+          exit 0
+        fi
+
+        git config user.name "github-actions[bot]"
+        git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+        git commit --amend --no-edit
+
+        if [ -n "$API_TOKEN" ] && [ -z "$SSH_KEY" ]; then
+          git remote set-url origin "https://x-access-token:${API_TOKEN}@github.com/${{ github.repository }}.git"
+        fi
+
+        git push --force-with-lease="refs/heads/$PR_BRANCH:$PR_HEAD_SHA" origin "HEAD:refs/heads/$PR_BRANCH"