test_helpers: Remove noop.

`BaseNotes(str, str).get_notes` does not do anything here.
It was introduced in
53888e5a26
by unintendedly.

Signed-off-by: Zixuan James Li <p359101898@gmail.com>

zerver/lib/test_helpers.py

@@ -45,7 +45,6 @@ from zerver.lib.avatar import avatar_url
 from zerver.lib.cache import get_cache_backend
 from zerver.lib.db import Params, ParamsT, Query, TimeTrackingCursor
 from zerver.lib.integrations import WEBHOOK_INTEGRATIONS
-from zerver.lib.notes import BaseNotes
 from zerver.lib.request import RequestNotes
 from zerver.lib.upload import LocalUploadBackend, S3UploadBackend
 from zerver.models import (
@@ -328,7 +327,6 @@ class HostRequestMock(HttpRequest):
         self.user = user_profile or AnonymousUser()
         self._body = b""
         self.content_type = ""
-        BaseNotes[str, str].get_notes
 
         RequestNotes.set_notes(
             self,