fix: [#2099] concurrency constraint for Storybook should only be on deploy

The concurrency constraint applied to all Storybook builds, not just
deploys, which meant that you would sometimes get failing storybook
CI on feature branches, where the build step is required to succeed.

Author: swrichards

.github/workflows/storybook.yml

@@ -15,11 +15,6 @@ on:
       - ready_for_review
   workflow_dispatch:
 
-# Allow one concurrent deployment
-concurrency:
-  group: 'pages-${{ github.ref_name }}' # unique builds for branch/tag name
-  cancel-in-progress: true
-
 jobs:
   storybook:
     name: Create storybook build
@@ -48,6 +43,11 @@ jobs:
       pages: write
       id-token: write
 
+    # Allow one concurrent deployment
+    concurrency:
+      group: 'pages-${{ github.ref_name }}' # unique builds for branch/tag name
+      cancel-in-progress: true
+
     runs-on: ubuntu-latest
     if: github.ref == 'refs/heads/develop' && github.event_name == 'push' # Exclude PRs
     needs: storybook