CI: Simplify update playwright expectations (maybe) (#5994)

## Summary

Follow-up to https://github.com/Comfy-Org/ComfyUI_frontend/pull/5985
See if it's possible to reduce the branching, maybe add reactions and a
Done comment?

## Changes

- **What**: Snapshot Update Updates

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5994-CI-Simplify-update-playwright-expectations-maybe-2876d73d365081eab031d8301c1360b7)
by [Unito](https://www.unito.io)

.github/workflows/update-playwright-expectations.yaml

@@ -7,6 +7,9 @@ on:
   issue_comment:
     types: [created]
 
+concurrency:
+  group: ${{ github.event.number || github.event.issue.number }}
+
 jobs:
   test:
     runs-on: ubuntu-latest
@@ -21,18 +24,36 @@ jobs:
         ) &&
         startsWith(github.event.comment.body, '/update-playwright') )
     steps:
+      - name: Find Update Comment
+        uses: peter-evans/find-comment@b30e6a3c0ed37e7c023ccd3f1db5c6c0b0c23aad
+        id: "find-update-comment"
+        with:
+          issue-number: ${{ github.event.number || github.event.issue.number }}
+          comment-author: "github-actions[bot]"
+          body-includes: "Updating Playwright Expectations"
+
+      - name: Add Starting Reaction
+        uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9
+        with:
+          comment-id: ${{ steps.find-update-comment.outputs.comment-id }}
+          issue-number: ${{ github.event.number || github.event.issue.number }}
+          body: |
+            Updating Playwright Expectations
+          edit-mode: replace
+          reactions: eyes
+
+      - name: Get Branch SHA
+        id: "get-branch"
+        run: echo ::set-output name=branch::$(gh pr view $PR_NO --repo $REPO --json headRefName --jq '.headRefName')
+        env:
+          REPO: ${{ github.repository }}
+          PR_NO: ${{ github.event.number || github.event.issue.number }}
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
       - name: Initial Checkout
         uses: actions/checkout@v5
-      - name: Pull Request Checkout (from comment)
-        run: gh pr checkout ${{ github.event.issue.number }}
-        if: github.event_name == 'issue_comment'
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - name: Pull Request Checkout (from label)
-        run: |
-          git fetch origin ${{ github.head_ref }}
-          git checkout ${{ github.head_ref }}
-        if: github.event_name == 'pull_request'
+        with:
+          ref: ${{ steps.get-branch.outputs.branch }}
       - name: Setup Frontend
         uses: ./.github/actions/setup-frontend
       - name: Setup Playwright
@@ -51,6 +72,7 @@ jobs:
       - name: Debugging info
         run: |
           echo "PR: ${{ github.event.issue.number }}"
+          echo "Branch: ${{ steps.get-branch.outputs.branch }}"
           git status
         working-directory: ComfyUI_frontend
       - name: Commit updated expectations
@@ -62,16 +84,19 @@ jobs:
             echo "No changes to commit"
           else
             git commit -m "[automated] Update test expectations"
-            if [ "${{ github.event_name }}" = "pull_request" ]; then
-              git push origin HEAD:${{ github.head_ref }}
-            else
-              git push
-            fi
+            git push origin ${{ steps.get-branch.outputs.branch }}
           fi
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         working-directory: ComfyUI_frontend
 
+      - name: Add Done Reaction
+        uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9
+        if: github.event_name == 'issue_comment'
+        with:
+          comment-id: ${{ steps.find-update-comment.outputs.comment-id }}
+          issue-number: ${{ github.event.number || github.event.issue.number }}
+          reactions: +1
+          reactions-edit-mode: replace
+
       - name: Remove New Browser Test Expectations label
         if: always() && github.event_name == 'pull_request'
         run: gh pr edit ${{ github.event.pull_request.number }} --remove-label "New Browser Test Expectations"