Prevent main builds

Author: MrHinsh

.github/workflows/main.yml

@@ -31,6 +31,7 @@ jobs:
    # Setup & Configuration
   Setup:
     name: "Setup & Configuration "
+    if: ${{ !(github.event.pull_request.head.repo.fork && github.ref == 'refs/heads/main') }}
     runs-on: ubuntu-latest
     outputs:
       GitVersion_BranchName: ${{ steps.gitversion.outputs.GitVersion_BranchName }}