Remove duplicate steps in Visual Test workflow (#7557)

### WHY are these changes introduced?

The current `vistest.yaml` GitHub workflow has a few duplicate steps.

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  Context about the problem that’s being addressed.
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### WHAT is this pull request doing?

Removes the duplicate Node setup, git checkout, and cache restore steps.

Author: sam-b-rose

.github/workflows/vistest.yml

@@ -12,16 +12,16 @@ jobs:
       github.event.issue.pull_request && github.event.comment.body == '/vistest'
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout branch
-        uses: actions/checkout@v3
-
-      - name: Setup Node with v16.13.0
-        uses: actions/setup-node@v3
+      - name: Enforce permission requirement
+        uses: prince-chrismc/check-actor-permissions-action@v1
         with:
           permission: write
 
-      - name: Restore cache
-        uses: actions/cache@v3
+      - name: Validate pull request is not on forked repo
+        uses: actions/github-script@v6
+        id: pr_data
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           script: |
             try {