test: Unskip a bulkinsert test case (#28780)

Unskip a bulkinsert test case which is skipped by #28209

pr: https://github.com/milvus-io/milvus/pull/28679

Signed-off-by: yhmo <yihua.mo@zilliz.com>

tests/python_client/testcases/test_bulk_insert.py

@@ -857,7 +857,6 @@ class TestBulkInsert(TestcaseBaseBulkInsert):
     @pytest.mark.parametrize("dim", [13])
     @pytest.mark.parametrize("entities", [150])
     @pytest.mark.parametrize("file_nums", [10])
-    @pytest.mark.skip(reason="issue #28209")
     def test_partition_key_on_multi_numpy_files(
             self, auto_id, dim, entities, file_nums
     ):