test: add fixture for license

conftest.py

@@ -102,7 +102,7 @@ def owned_image(image_file, common_user1) -> Image:
 
 @pytest.fixture
 def public_domain_license() -> License:
-    return LicenseFactory()
+    return LicenseFactory(identifier="pd", name="Public Domain")
 
 
 @pytest.fixture
@@ -301,3 +301,8 @@ def topic() -> Topic:
 @pytest.fixture
 def owner() -> User:
     return OwnerFactory()
+
+
+@pytest.fixture
+def license_() -> License:
+    return LicenseFactory()