Remove unused `# type: ignore`s (#12531)

Over time we've begun to use newer versions of mypy, typeshed, stub
packages---and of course we've improved our own annotations. This makes
some type ignore comments no longer necessary. I have removed them.

There was one exception: a module that imports `select.epoll`. The
ignore is redundant on Linux, but I've kept it ignored for those of us
who work on the source tree using not-Linux. (#11771)

I'm more interested in the config line which enforces this. I want
unused ignores to be reported, because I think it's useful feedback when
annotating to know when you've fixed a problem you had to previously
ignore.

* Installing extras before typechecking

Lacking an easy way to install all extras generically, let's bite the bullet and
make install the hand-maintained `all` extra before typechecking.

Now that https://github.com/matrix-org/backend-meta/pull/6 is merged to
the release/v1 branch.

3 files changed, 5 insertions, 5 deletions

diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 86991d26ce..22678d486d 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -481,7 +481,7 @@ class AuthHandler:
             sid = authdict["session"]
 
         # Convert the URI and method to strings.
-        uri = request.uri.decode("utf-8")  # type: ignore
+        uri = request.uri.decode("utf-8")
         method = request.method.decode("utf-8")
 
         # If there's no session ID, create a new session.
diff --git a/synapse/handlers/oidc.py b/synapse/handlers/oidc.py
index 724b9cfcb4..f6ffb7d18d 100644
--- a/synapse/handlers/oidc.py
+++ b/synapse/handlers/oidc.py
@@ -966,7 +966,7 @@ class OidcProvider:
                         "Mapping provider does not support de-duplicating Matrix IDs"
                     )
 
-                attributes = await self._user_mapping_provider.map_user_attributes(  # type: ignore
+                attributes = await self._user_mapping_provider.map_user_attributes(
                     userinfo, token
                 )
 
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index 102dd4b57d..5619f8f50e 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -357,7 +357,7 @@ class SearchHandler:
             itertools.chain(
                 # The events_before and events_after for each context.
                 itertools.chain.from_iterable(
-                    itertools.chain(context["events_before"], context["events_after"])  # type: ignore[arg-type]
+                    itertools.chain(context["events_before"], context["events_after"])
                     for context in contexts.values()
                 ),
                 # The returned events.
@@ -373,10 +373,10 @@ class SearchHandler:
 
         for context in contexts.values():
             context["events_before"] = self._event_serializer.serialize_events(
-                context["events_before"], time_now, bundle_aggregations=aggregations  # type: ignore[arg-type]
+                context["events_before"], time_now, bundle_aggregations=aggregations
             )
             context["events_after"] = self._event_serializer.serialize_events(
-                context["events_after"], time_now, bundle_aggregations=aggregations  # type: ignore[arg-type]
+                context["events_after"], time_now, bundle_aggregations=aggregations
             )
 
         results = [