[Python fix-it][Gevent] Enable gevent _dynamic_stubs_test (#32842)

Re-enable this test since it's now passing after gevent
reimplementation.

Fix: https://github.com/grpc/grpc/issues/15411

bazel/gevent_test.bzl

@@ -76,6 +76,7 @@ def py_grpc_gevent_test(
     native.py_test(
         name = name + ".gevent",
         args = [name],
+        data = data,
         deps = augmented_deps,
         srcs = [copied_main_filename],
         main = copied_main_filename,

src/python/grpcio_tests/tests/unit/_dynamic_stubs_test.py

@@ -126,8 +126,6 @@ def _test_grpc_tools_unimportable():
 # when they do not come from the "__main__" module, so this test passes
 # if run directly on Windows, but not if started by the test runner.
 @unittest.skipIf(os.name == "nt", "Windows multiprocessing unsupported")
-@unittest.skipIf(test_common.running_under_gevent(),
-                 "Import paths do not work with gevent runner.")
 class DynamicStubTest(unittest.TestCase):
 
     def test_sunny_day(self):