dx: compact storybook PR comment to single-line header (#9078)

## Summary

Compact the Storybook build status PR comment to a single-line header
with collapsible details, matching the approach from #8677.

## Changes

- **Starting**: Collapsed from multi-line with build steps to `## 🎨
Storybook: ⏳ Building...`
- **Completed (success)**: `## 🎨 Storybook: ✅ Built — [View
Storybook](url)` with timestamp/links in `<details>`
- **Completed (failure)**: `## 🎨 Storybook: ❌ Failed` with details
collapsed
- Removed version-bump branch check (starting comment no longer varies
by branch type)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9078-dx-compact-storybook-PR-comment-to-single-line-header-30f6d73d365081b98666c48a94542b70)
by [Unito](https://www.unito.io)

.github/workflows/ci-tests-e2e-forks.yaml

@@ -6,9 +6,6 @@ on:
     workflows: ['CI: Tests E2E']
     types: [requested, completed]
 
-env:
-  DATE_FORMAT: '+%m/%d/%Y, %I:%M:%S %p'
-
 jobs:
   deploy-and-comment-forked-pr:
     runs-on: ubuntu-latest
@@ -63,8 +60,7 @@ jobs:
           ./scripts/cicd/pr-playwright-deploy-and-comment.sh \
             "${{ steps.pr.outputs.result }}" \
             "${{ github.event.workflow_run.head_branch }}" \
-            "starting" \
-            "$(date -u '${{ env.DATE_FORMAT }}')"
+            "starting"
 
       - name: Download and Deploy Reports
         if: steps.pr.outputs.result != 'null' && github.event.action == 'completed'