fix(test): fix test_get_lgpl_license_not_found JSONDecodeError

The test had two issues:
1. Too-broad mock: patching pathlib.Path.exists globally broke
   Starlette/FastAPI internals. Now targets the specific module.
2. Wrong assertion: response.json() failed because the custom
   HTTPException handler returns HTML for non-API routes, not JSON.
   Updated to only assert on status code.

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

tests/test_views_license.py

@@ -27,10 +27,10 @@ class TestLicenseViews:
 
     def test_get_lgpl_license_not_found(self, client):
         """Test LGPL license file not found."""
-        with patch("pathlib.Path.exists", return_value=False):
+        with patch("app.views.license_routes.Path") as MockPath:
+            MockPath.return_value.exists.return_value = False
             response = client.get("/licenses/lgpl.txt")
             assert response.status_code == 404
-            assert "not found" in response.json()["detail"].lower()
 
     def test_serve_attribution_page(self, client):
         """Test attribution page is served."""