fix: remove the deployed storybook when the PR is closed (#11)

# Description

- Add on-pull-request-close workflow

## Reason

The deployment only runs when the build ran previously.
However we need to run the deployment step when the PR is closed in
order to clean up the deployed storybook, without having to run the
build step again.

---

<!-- Auto-generated section. DO NOT DELETE -->

.github/workflows/on-pull-request-close.yml

@@ -0,0 +1,18 @@
+name: Feature Branch
+
+on:
+  pull_request:
+    types:
+      - closed
+
+concurrency: preview-${{ github.ref }}
+
+jobs:
+  clean-deployment:
+    if: github.event.action == 'closed' && github.event.pull_request.draft == false
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Deploy preview
+        uses: rossjrw/pr-preview-action@v1
+        with:
+          custom-url: percoct-ui.yld.engineering

.github/workflows/on-pull-request.yml

@@ -26,20 +26,19 @@ jobs:
   deployment:
     runs-on: ubuntu-20.04
     needs: ["build"]
+    if: github.event.action != 'closed' && github.event.pull_request.draft == false
     environment:
       name: github-pages
       url: ${{ steps.preview.outputs.deployment-url }}
     outputs:
       environment_url: ${{ steps.preview.outputs.deployment-url }}
     steps:
       - name: Checkout
-        if: github.event.action != 'closed' && github.event.pull_request.draft == false
         uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
       - uses: actions/download-artifact@v4
-        if: github.event.action != 'closed' && github.event.pull_request.draft == false
         with:
           name: storybook-static
           path: ./storybook-static/