Remove xfail annotations from passing tests (#296)

Author: evertlammerts

tests/fast/test_filesystem.py

@@ -56,12 +56,10 @@ def add_file(fs, filename=FILENAME):
 
 
 class TestPythonFilesystem:
-    @pytest.mark.xfail(reason="Unregister support was removed. Should be added back before release.")
     def test_unregister_non_existent_filesystem(self, duckdb_cursor: DuckDBPyConnection):
         with pytest.raises(InvalidInputException):
             duckdb_cursor.unregister_filesystem("fake")
 
-    @pytest.mark.xfail(reason="Unregister support was removed. Should be added back before release.")
     def test_memory_filesystem(self, duckdb_cursor: DuckDBPyConnection, memory: fsspec.AbstractFileSystem):
         duckdb_cursor.register_filesystem(memory)