Try to simplify for comparing forks

.github/workflows/validate-schemas.yml

@@ -22,13 +22,7 @@ jobs:
  - name: Checkout
  uses: actions/checkout@v4
  with:
- repository: ${{ github.event.pull_request.head.repo.full_name }}
- ref: ${{ github.event.pull_request.head.ref }}
-
- - name: Fetch compare
- run: |
- git remote add upstream ${{ github.event.pull_request.base.repo.repositoryUrl }}
- git fetch --no-write-fetch-head --depth=1 upstream ${{ github.event.pull_request.base.ref }}
+ fetch-depth: 2
 
  - name: Setup Node
  uses: actions/setup-node@v4
@@ -40,4 +34,4 @@ jobs:
  run: npm ci
 
  - name: Validate JSON files
- run: node theme-utils.mjs validate-schema $(git diff --name-only upstream/${{ github.event.pull_request.base.ref }} ${{ github.event.pull_request.head.ref }} -- ${{ env.PR_PATHS }} | tr '\n' ' ')
+ run: node theme-utils.mjs validate-schema $(git diff --name-only origin/${{ github.base_ref }}...HEAD -- ${{ env.PR_PATHS }} | tr '\n' ' ')