Update peter-evans/repository-dispatch action to v4

Author: renovate[bot]

.github/workflows/test-projects.yml

@@ -21,7 +21,7 @@ jobs:
           - "packagist/private-packagist"
 
     steps:
-      - uses: peter-evans/repository-dispatch@v3
+      - uses: peter-evans/repository-dispatch@v4
         with:
           token: ${{ secrets.REPO_ACCESS_TOKEN }}
           repository: "${{ matrix.repository }}"