ci: use workflow to request bonsai rebuild

instead of webhook. For details, see:
https://discourse.sensu.io/t/heads-up-new-feature-in-bonsai-for-asset-developers/2866

Author: teutat3s

.github/workflows/bonsai-rebuild.yml

@@ -0,0 +1,20 @@
+# https://discourse.sensu.io/t/heads-up-new-feature-in-bonsai-for-asset-developers/2866
+name: Bonsai Request Rebuild
+
+on:
+  workflow_run:
+    workflows:
+      - svenstaro/upload-release-action
+    types:
+      - completed
+
+jobs:
+  bonsai-build:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+    steps:
+      - name: request bonsai rebuild
+        run: >
+          curl -v -XPOST
+          -H "X-GitHub-Token: ${{ secrets.BONSAI_GITHUB_TOKEN }}"
+          --url "https://bonsai.sensu.io/assets/${{ github.repository }}/build"