[Misc] Auto-format tests. (#5313)

* [Misc] Auto-format tests.

* more

---------
Co-authored-by: Ubuntu <ubuntu@ip-172-31-28-63.ap-northeast-1.compute.internal>

tests/python/common/test_merge.py

 import backend as F
-from test_utils import parametrize_idtype
 
 import dgl
+from test_utils import parametrize_idtype
 
 
 @parametrize_idtype

tests/python/common/test_partition.py

 import unittest
 
 import backend as F
-from test_utils import parametrize_idtype
 
 from dgl.distributed import graph_partition_book as gpb
 from dgl.partition import NDArrayPartition
+from test_utils import parametrize_idtype
 
 
 @unittest.skipIf(
@@ -13,13 +13,13 @@ from dgl.partition import NDArrayPartition
 )
 @parametrize_idtype
 def test_get_node_partition_from_book(idtype):
-    node_map = {'_N': F.tensor([[0, 3], [4, 5], [6, 10]], dtype=idtype)}
-    edge_map = {('_N', '_E', '_N'): F.tensor([[0, 9], [10, 15], [16, 25]], dtype=idtype)}
+    node_map = {"_N": F.tensor([[0, 3], [4, 5], [6, 10]], dtype=idtype)}
+    edge_map = {
+        ("_N", "_E", "_N"): F.tensor([[0, 9], [10, 15], [16, 25]], dtype=idtype)
+    }
     ntypes = {ntype: i for i, ntype in enumerate(node_map)}
     etypes = {etype: i for i, etype in enumerate(edge_map)}
-    book = gpb.RangePartitionBook(
-        0, 3, node_map, edge_map, ntypes, etypes
-    )
+    book = gpb.RangePartitionBook(0, 3, node_map, edge_map, ntypes, etypes)
     partition = gpb.get_node_partition_from_book(book, F.ctx())
     assert partition.num_parts() == 3
     assert partition.array_size() == 11

tests/python/common/test_propagate.py

 import unittest
 
 import backend as F
+
+import dgl
 import networkx as nx
 import utils as U
 from test_utils import parametrize_idtype
 
-import dgl
-
 
 def create_graph(idtype):
     g = dgl.from_networkx(nx.path_graph(5), idtype=idtype, device=F.ctx())

tests/python/common/test_random.py

 import unittest
 
 import backend as F
-import numpy as np
 
 import dgl
+import numpy as np
 
 
 @unittest.skipIf(

tests/python/common/test_readout.py

 import unittest
 
 import backend as F
+
+import dgl
 import networkx as nx
 import numpy as np
 import pytest
 from test_utils import parametrize_idtype
 from test_utils.graph_cases import get_cases
 
-import dgl
-
 
 @parametrize_idtype
 def test_sum_case1(idtype):