refactor: extract shared resolve-pr-from-workflow-run action (#11336)

## Summary

Extract duplicated PR-number-resolution logic from
`workflow_run`-triggered workflows into a shared composite action at
`.github/actions/resolve-pr-from-workflow-run/`.

## Changes

- **What**: New composite action that resolves PR number from
`workflow_run` context using `pull_requests[0]` with
`listPullRequestsAssociatedWithCommit` fallback. Updated 4 consumer
workflows; removed dead artifact-stored PR metadata from 2 CI workflows.
- **Files touched**:
  - `.github/actions/resolve-pr-from-workflow-run/action.yaml` (new)
- `.github/workflows/pr-vercel-website-preview.yaml` (uses shared
action)
- `.github/workflows/pr-report.yaml` (uses shared action with
`check-staleness: true`)
- `.github/workflows/ci-tests-storybook-forks.yaml` (replaced
`pulls.list` scan)
- `.github/workflows/ci-tests-e2e-forks.yaml` (replaced `pulls.list`
scan)
- `.github/workflows/ci-size-data.yaml` (removed dead
`number.txt`/`base.txt`/`head-sha.txt` writes)
- `.github/workflows/ci-perf-report.yaml` (removed dead `perf-meta`
artifact)

## Review Focus

- The fork workflows previously used `pulls.list` (fetches all open PRs,
linear scan by SHA). The shared action uses the more targeted
`workflow_run.pull_requests[0]` + `listPullRequestsAssociatedWithCommit`
fallback.
- `coverage-slack-notify.yaml` was intentionally left unchanged — it
parses merged commit messages on `main` pushes, which is a different use
case.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-11336-refactor-extract-shared-resolve-pr-from-workflow-run-action-3456d73d365081e5b8f5ea29c020763e)
by [Unito](https://www.unito.io)

---------

Co-authored-by: bymyself <cbyrne@comfy.org>
Co-authored-by: Amp <amp@ampcode.com>

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

@@ -6,6 +6,10 @@ on:
     workflows: ['CI: Tests E2E']
     types: [requested, completed]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.workflow_run.head_repository.full_name }}-${{ github.event.workflow_run.head_branch }}
+  cancel-in-progress: true
+
 jobs:
   deploy-and-comment-forked-pr:
     runs-on: ubuntu-latest
@@ -30,40 +34,23 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v6
 
-      - name: Get PR Number
+      - name: Resolve PR from workflow_run context
         id: pr
-        uses: actions/github-script@v8
-        with:
-          script: |
-            const { data: prs } = await github.rest.pulls.list({
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              state: 'open',
-            });
-
-            const pr = prs.find(p => p.head.sha === context.payload.workflow_run.head_sha);
-
-            if (!pr) {
-              console.log('No PR found for SHA:', context.payload.workflow_run.head_sha);
-              return null;
-            }
-
-            console.log(`Found PR #${pr.number} from fork: ${context.payload.workflow_run.head_repository.full_name}`);
-            return pr.number;
+        uses: ./.github/actions/resolve-pr-from-workflow-run
 
       - name: Handle Test Start
-        if: steps.pr.outputs.result != 'null' && github.event.action == 'requested'
+        if: steps.pr.outputs.skip != 'true' && github.event.action == 'requested'
         env:
           GITHUB_TOKEN: ${{ github.token }}
         run: |
           chmod +x scripts/cicd/pr-playwright-deploy-and-comment.sh
           ./scripts/cicd/pr-playwright-deploy-and-comment.sh \
-            "${{ steps.pr.outputs.result }}" \
+            "${{ steps.pr.outputs.number }}" \
             "${{ github.event.workflow_run.head_branch }}" \
             "starting"
 
       - name: Download and Deploy Reports
-        if: steps.pr.outputs.result != 'null' && github.event.action == 'completed'
+        if: steps.pr.outputs.skip != 'true' && github.event.action == 'completed'
         uses: actions/download-artifact@v7
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -72,7 +59,7 @@ jobs:
           path: reports
 
       - name: Handle Test Completion
-        if: steps.pr.outputs.result != 'null' && github.event.action == 'completed'
+        if: steps.pr.outputs.skip != 'true' && github.event.action == 'completed'
         env:
           CLOUDFLARE_API_TOKEN: ${{ secrets.CLOUDFLARE_API_TOKEN }}
           CLOUDFLARE_ACCOUNT_ID: ${{ secrets.CLOUDFLARE_ACCOUNT_ID }}
@@ -85,6 +72,6 @@ jobs:
 
           chmod +x scripts/cicd/pr-playwright-deploy-and-comment.sh
           ./scripts/cicd/pr-playwright-deploy-and-comment.sh \
-            "${{ steps.pr.outputs.result }}" \
+            "${{ steps.pr.outputs.number }}" \
             "${{ github.event.workflow_run.head_branch }}" \
             "completed"