bpo-34184: Fix running Lib/test/test_dataclasses.py as a script. (GH-8382) (GH-8421)

(cherry picked from commit 3fe5cccb08283f5f4817ac432560972a4c0f5290)
diff --git a/Lib/test/test_dataclasses.py b/Lib/test/test_dataclasses.py
index d9556c7..c5140e8 100755
--- a/Lib/test/test_dataclasses.py
+++ b/Lib/test/test_dataclasses.py
@@ -1966,7 +1966,7 @@
         @dataclass(repr=False)
         class C:
             x: int
-        self.assertIn('test_dataclasses.TestRepr.test_no_repr.<locals>.C object at',
+        self.assertIn(f'{__name__}.TestRepr.test_no_repr.<locals>.C object at',
                       repr(C(3)))
 
         # Test a class with a __repr__ and repr=False.
@@ -2713,10 +2713,10 @@
                 self.assertEqual(C(10).x, 10)
 
     def test_classvar_module_level_import(self):
-        from . import dataclass_module_1
-        from . import dataclass_module_1_str
-        from . import dataclass_module_2
-        from . import dataclass_module_2_str
+        from test import dataclass_module_1
+        from test import dataclass_module_1_str
+        from test import dataclass_module_2
+        from test import dataclass_module_2_str
 
         for m in (dataclass_module_1, dataclass_module_1_str,
                   dataclass_module_2, dataclass_module_2_str,