synapse: 1.34.0 -> 1.35.0

[sumnerevans]

Motivation for this change

Tracking PR for Synapse 1.35.0.

https://github.com/matrix-org/synapse/blob/develop/CHANGES.md#synapse-1350rc1-2021-05-25
https://github.com/matrix-org/synapse/blob/v1.35.0rc2/CHANGES.md#synapse-1350rc2-2021-05-27
https://github.com/matrix-org/synapse/releases/tag/v1.35.0rc3
https://github.com/matrix-org/synapse/releases/tag/v1.35.0

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Added a release notes entry if the change is major or breaking
• Fits CONTRIBUTING.md.

[andir]

Might be worth to create a follow-up PR that updates our systemd units: https://github.com/matrix-org/synapse/pull/9803/files

[sumnerevans]

Might be worth to create a follow-up PR that updates our systemd units: https://github.com/matrix-org/synapse/pull/9803/files

I'd like to get #120260 in before making those updates as there will be a lot of merge conflicts otherwise.

[github-actions]

Successfully created backport PR #125425 for release-21.05.

[github-actions]

The process '/usr/bin/git' failed with exit code 1

[Ma27]

FYI back when I updated matrix-synapse, I had a "backport-by-default" policy. I'll try to briefly explain the why: synapse regularly has CVEs that have to be patched and those are usually released on new minors. From my experience it's less painful to have regular updates rather than a "big" update when it's necessary.

Also, there were non-trivial infra changes in the past that made synapse upgrades mandatory under certain circumstances, see for instance https://github.com/matrix-org/synapse/blob/develop/UPGRADE.rst#3pid-verification-changes.

cc @domenkozar for the The process '/usr/bin/git' failed with exit code 1-error. Not sure what's that about :)

[sumnerevans]

@Ma27 thanks for explaining. I'll add that to future PRs for matrix-synapse upgrades.

Also, I've been updating matrix-synapse the the bleeding edge for my own servers, so that's why I figured I should just do it in nixpkgs as well. If you would rather handle it yourself, let me know and I'll step back :)