Bump cheroot from 8.6.0 to 9.0.0 (#1903)

* Bump cheroot from 8.6.0 to 9.0.0

Bumps [cheroot](https://github.com/cherrypy/cheroot) from 8.6.0 to 9.0.0.
- [Release notes](https://github.com/cherrypy/cheroot/releases)
- [Changelog](https://github.com/cherrypy/cheroot/blob/main/CHANGES.rst)
- [Commits](https://github.com/cherrypy/cheroot/compare/v8.6.0...v9.0.0)

---
updated-dependencies:
- dependency-name: cheroot
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update cheroot==9.0.0

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: JonnyWong16 <9099342+JonnyWong16@users.noreply.github.com>

[skip ci]

lib/cheroot/testing.py

@@ -1,16 +1,13 @@
 """Pytest fixtures and other helpers for doing testing by end-users."""
 
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
-from contextlib import closing
+from contextlib import closing, contextmanager
 import errno
 import socket
 import threading
 import time
+import http.client
 
 import pytest
-from six.moves import http_client
 
 import cheroot.server
 from cheroot.test import webtest
@@ -33,6 +30,7 @@ config = {
 }
 
 
+@contextmanager
 def cheroot_server(server_factory):
     """Set up and tear down a Cheroot server instance."""
     conf = config[server_factory].copy()
@@ -64,14 +62,14 @@ def cheroot_server(server_factory):
 @pytest.fixture
 def wsgi_server():
     """Set up and tear down a Cheroot WSGI server instance."""
-    for srv in cheroot_server(cheroot.wsgi.Server):
+    with cheroot_server(cheroot.wsgi.Server) as srv:
         yield srv
 
 
 @pytest.fixture
 def native_server():
     """Set up and tear down a Cheroot HTTP server instance."""
-    for srv in cheroot_server(cheroot.server.HTTPServer):
+    with cheroot_server(cheroot.server.HTTPServer) as srv:
         yield srv
 
 
@@ -89,9 +87,9 @@ class _TestClient:
             port=self._port,
         )
         conn_cls = (
-            http_client.HTTPConnection
+            http.client.HTTPConnection
             if self.server_instance.ssl_adapter is None else
-            http_client.HTTPSConnection
+            http.client.HTTPSConnection
         )
         return conn_cls(name)