Merge branch 'develop' of github.com:matrix-org/synapse into anoa/improve_test_times

* 'develop' of github.com:matrix-org/synapse: (148 commits)
  Add script for finding files with unix line terminators (#7965)
  Convert the remaining media repo code to async / await. (#7947)
  Convert a synapse.events to async/await. (#7949)
  Convert groups and visibility code to async / await. (#7951)
  Convert push to async/await. (#7948)
  update changelog
  1.18.0rc1
  Fix error reporting when using `opentracing.trace` (#7961)
  Fix typing replication not being handled on master (#7959)
  Remove hacky error handling for inlineDeferreds. (#7950)
  Convert tests/rest/admin/test_room.py to unix file endings (#7953)
  Support oEmbed for media previews. (#7920)
  Convert state resolution to async/await (#7942)
  Fix up types and comments that refer to Deferreds. (#7945)
  Do not convert async functions to Deferreds in the interactive_auth_handler (#7944)
  Convert more of the media code to async/await (#7873)
  Return an empty body for OPTIONS requests. (#7886)
  Downgrade warning on client disconnect to INFO (#7928)
  Convert presence handler helpers to async/await. (#7939)
  Update the auth providers to be async. (#7935)
  ...

Author: anoadragon453