Synapse 1.39.0 released

Synapse 1.39.0 is now available!

We've done quite a bit of work this release on Synapse's new interface for extension modules:

• Synapse's account_validity option has been extracted into a built-in extension module. If your configuration previously enabled account_validity, it will continue working as before, but it is now easier to override and customize.
• The third party event rules callbacks have also been experimentally ported to the new module interface.

We've also improved the Space Summary API to list all rooms which a user could join (#10298). This is especially important with the pending standardization of Room Version 8, which includes MSC3083: Restricting room membership based on membership in other rooms.

MadLittleMods landed several pull requests on the path to implementing MSC2716: Incrementally importing history into existing rooms (#10250, #10276).

More than anything else, this release contains an absolutely enormous load of internal cleanup. For example:

• ShadowJonathan ran pyupgrade on the entire codebase, bringing it up to modern Py3.6+ conventions, then separately used com2ann to move us from legacy # type: foo type hints to more modern inline annotations.
• We finished converting several integer columns in our database to bigint as a precautionary measure.
• We've made innumerable improvements to our CI configuration; including moving completely to GitHub Actions.
• Countless small improvements to performance, reliability, and error logging.

But that's not all! Synapse 1.39 also allows for setting credentials for HTTP proxy connections thanks to work by dklimpel; previously, Synapse was only able to provide authentication for HTTPS proxies.

Please see the Upgrade Notes and Release Notes for a complete list of changes in this rele ase.

Synapse is a Free and Open Source Software project, and we'd like to extend our thanks to everyone who contributed to this release, including andir, dklimpel, ilmari, LukeWalsh, moritzdietz, ShadowJonathan, and xmunoz.