Merge branch 'develop' into rav/module_api_extensions

CHANGES.md

INSTALL.md

UPGRADE.rst

changelog.d/6655.misc

changelog.d/6667.misc

changelog.d/6675.removal

changelog.d/6681.feature

changelog.d/6682.bugfix

changelog.d/6686.misc

changelog.d/6687.misc

changelog.d/6689.misc

changelog.d/6690.bugfix

changelog.d/6691.misc

changelog.d/6697.misc

changelog.d/6698.doc

docs/admin_api/media_admin_api.md

docs/workers.md

scripts/synapse_port_db

synapse/api/errors.py

synapse/app/homeserver.py