Check license in CI

Author: joerivanruth

.github/workflows/unittests.yml

@@ -41,3 +41,10 @@ jobs:
       - run: cargo test --lib --examples --all-features
 
       - run: cargo tree
+
+  checklicense:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - run: ./checklicense.py --check