Update tests/data/test_optimization_indexset.py

Co-authored-by: Fridolin Glatter <[email protected]>

tests/data/test_optimization_indexset.py

@@ -184,6 +184,6 @@ def test_add_elements(self, platform: ixmp4.Platform):
             elements=test_elements_2,  # type:ignore
         )
         indexset_5 = platform.backend.optimization.indexsets.get(
-            run_id=run.id, name="IndexSet 5"
+            run_id=run.id, name=indexset_5.name
         )
         assert indexset_5.elements == test_elements_2