Fix names of type annotations not matching between definition and use.

[jcferretti]

Somehow the github test runs miss this, but if you try to run tests locally with ./gradlew :py-client:testPyClient, you get failures due to the type annotation name mismatch:

[...]
> Task :py-client:testPyClientRun FAILED
Created container with ID '490146f474607a404c8d35e0d4641b3fa8dc8e03bbbc1bdbb69779780cb5bcb7'.
Container exited with code 1

Running tests...
----------------------------------------------------------------------
  test_console (unittest.loader._FailedTest) ... ERROR (0.001s)
  test_multi_session (unittest.loader._FailedTest) ... ERROR (0.000s)
  test_plugin_client (unittest.loader._FailedTest) ... ERROR (0.000s)
  test_query (unittest.loader._FailedTest) ... ERROR (0.000s)
  test_session (unittest.loader._FailedTest) ... ERROR (0.000s)
  test_table (unittest.loader._FailedTest) ... ERROR (0.000s)
  test_updateby (unittest.loader._FailedTest) ... ERROR (0.000s)
  testbase (unittest.loader._FailedTest) ... ERROR (0.000s)

======================================================================
ERROR [0.001s]: test_console (unittest.loader._FailedTest)
----------------------------------------------------------------------
ImportError: Failed to import test module: test_console
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/unittest/loader.py", line 436, in _find_test_path
    module = self._get_module_from_name(name)
  File "/usr/local/lib/python3.10/unittest/loader.py", line 377, in _get_module_from_name
    __import__(name)
  File "/project/tests/test_console.py", line 9, in <module>
    from pydeephaven import DHError
  File "/project/pydeephaven/__init__.py", line 28, in <module>
    from .session import Session
  File "/project/pydeephaven/session.py", line 87, in <module>
    class Session:
  File "/project/pydeephaven/session.py", line 225, in Session
    def wrap_rpc(self, stub_call: NotBidiRpc, *args, **kwargs) -> Any:
NameError: name 'NotBidiRpc' is not defined
[...]