ci: gate PR preview builds (#603)

* ci: gate PR preview builds

* ci: include setup action in preview trigger

Author: thymikee

.github/workflows/pr-preview-cleanup.yml

@@ -0,0 +1,30 @@
+name: Cleanup PR previews
+
+on:
+  pull_request:
+    types:
+      - closed
+
+concurrency: preview-${{ github.ref }}
+
+jobs:
+  cleanup-preview:
+    if: github.event.pull_request.head.repo.full_name == github.repository
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+      pages: write
+    steps:
+      - name: Checkout
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+        with:
+          persist-credentials: true
+
+      - name: Remove preview
+        uses: rossjrw/pr-preview-action@ffa7509e91a3ec8dfc2e5536c4d5c1acdf7a6de9 # v1.8.1
+        with:
+          source-dir: website/doc_build
+          preview-branch: gh-pages
+          qr-code: true
+          wait-for-pages-deployment: true

.github/workflows/pr-preview.yml

@@ -6,7 +6,14 @@ on:
       - opened
       - reopened
       - synchronize
-      - closed
+    paths:
+      - "website/**"
+      - ".github/actions/build-docs/action.yml"
+      - ".github/actions/setup-node-pnpm/action.yml"
+      - ".github/workflows/pr-preview.yml"
+      - "package.json"
+      - "pnpm-lock.yaml"
+      - "pnpm-workspace.yaml"
 
 concurrency: preview-${{ github.ref }}