Add gate to prevent attempt to run on fork (#721)

Author: e3b0c442

.github/workflows/pr-license-scan.yaml

@@ -6,6 +6,7 @@ on:
 jobs:
   fossa-scan:
     runs-on: ubuntu-latest
+    if: github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository
     steps:
       - uses: actions/checkout@v3
       - name: "Run FOSSA Analyze"