Support reactor timing metric on more reactors. (#16532)

Previously only Twisted's EPollReactor was compatible with the
reactor timing metric, notably not working when asyncio was used.

After this change, the following configurations support the reactor
timing metric:

* poll, epoll, or select reactors
* asyncio reactor with a poll, epoll, select, /dev/poll, or kqueue event loop.

1 files changed, 2 insertions, 2 deletions

diff --git a/mypy.ini b/mypy.ini

index fdfe9432fc..1a2b9ea410 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -37,8 +37,8 @@ files =
   build_rust.py
 
 [mypy-synapse.metrics._reactor_metrics]
-# This module imports select.epoll. That exists on Linux, but doesn't on macOS.
-# See https://github.com/matrix-org/synapse/pull/11771.
+# This module  pokes at the internals of OS-specific classes, to appease mypy
+# on different systems we add additional ignores.
 warn_unused_ignores = False
 
 [mypy-synapse.util.caches.treecache]