Fetch source projects of requests

We do not care for current devel project, but for the projects we saw
requests from

tests/tree_test.py

@@ -19,7 +19,7 @@ class TestTreeMethods(unittest.TestCase):
         for rev in data["revisions"]:
             DBRevision.import_fixture_dict(self.db, rev)
 
-        revisions = TreeBuilder(self.db).build(package)
+        revisions = TreeBuilder(self.db).build("openSUSE:Factory", package)
         path = os.path.join(
             os.path.dirname(__file__), f"fixtures/{package}-expected-tree.yaml"
         )