- Add type hints to `synapse.util`. ([\#11321](https://github.com/matrix-org/synapse/issues/11321), [\#11328](https://github.com/matrix-org/synapse/issues/11328))
- Improve type annotations in Synapse's test suite. ([\#11323](https://github.com/matrix-org/synapse/issues/11323), [\#11330](https://github.com/matrix-org/synapse/issues/11330))
- Test that room alias deletion works as intended. ([\#11327](https://github.com/matrix-org/synapse/issues/11327))
- Add type annotations for some methods and properties in the module API. ([\#11341](https://github.com/matrix-org/synapse/issues/11341))
- Fix running `scripts-dev/complement.sh`, which was broken in v1.47.0rc1. ([\#11368](https://github.com/matrix-org/synapse/issues/11368))
- Rename internal functions for token generation to better reflect what they do. ([\#11369](https://github.com/matrix-org/synapse/issues/11369), [\#11370](https://github.com/matrix-org/synapse/issues/11370))