Fixing that the validate-pull-request workflow should look for a parent PR in Lombiq/DotNest-Core-Sites-SDK

Author: BenedekFarkas

.github/workflows/validate-pull-request.yml

@@ -7,3 +7,5 @@ jobs:
   validate-pull-request:
     name: Validate Pull Request
     uses: Lombiq/GitHub-Actions/.github/workflows/validate-submodule-pull-request.yml@dev
+    with:
+      repository: Lombiq/DotNest-Core-Sites-SDK