github workflow: enable workflow approval

Allow to run GitHub workflows for Pull Requests that have the ok-to-test
label.

Signed-off-by: Ivan Valdes <ivan@vald.es>

.github/workflows/gh-workflow-approve.yaml

@@ -0,0 +1,42 @@
+---
+name: Approve GitHub Workflows
+
+on:
+  pull_request_target:
+    types:
+      - labeled
+      - synchronize
+    branches:
+      - main
+
+jobs:
+  approve:
+    name: Approve ok-to-test
+    if: contains(github.event.pull_request.labels.*.name, 'ok-to-test')
+    runs-on: ubuntu-latest
+    permissions:
+      actions: write
+    steps:
+      - name: Update PR
+        uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6.4.1
+        continue-on-error: true
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          debug: ${{ secrets.ACTIONS_RUNNER_DEBUG == 'true' }}
+          script: |
+            const result = await github.rest.actions.listWorkflowRunsForRepo({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              event: "pull_request",
+              status: "action_required",
+              head_sha: context.payload.pull_request.head.sha,
+              per_page: 100
+            });
+
+            for (var run of result.data.workflow_runs) {
+              await github.rest.actions.approveWorkflowRun({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                run_id: run.id
+              });
+            }