* commit 'cc40a59b4':
1.21.0
Add prometheus metrics to track federation delays (#8430)
Make token serializing/deserializing async (#8427)
Allow additional SSO properties to be passed to the client (#8413)
changelog
Add an improved "forward extremities" metric
Rewrite BucketCollector
Fix _exposition.py to stop stripping samples
Drop support for ancient prometheus_client (#8426)
Various clean ups to room stream tokens. (#8423)
changelog
Report state res metrics to Prometheus and log
Move Measure calls into `resolve_events_with_store`
Expose a `get_resource_usage` method in `Measure`
Move `resolve_events_with_store` into StateResolutionHandler