Dendrite invite fix

See merge request famedly/conduit!416

Fix CI

See merge request famedly/conduit!414

Cleanly handle invalid response from trusted server instead of panicking

See merge request famedly/conduit!411

Fix typing indicators and unencrypted messages in encrypted rooms

See merge request famedly/conduit!409

fix: HEAD requests should continue to produce METHOD_NOT_ALLOWED

See merge request famedly/conduit!402

fix: element android did not reset notification counts

See merge request famedly/conduit!408

Update nginx configuration to allow for larger uploads.

See merge request famedly/conduit!407

add nix flake

See merge request famedly/conduit!403

Return 403 to 3pid token routes to signal not implemented

See merge request famedly/conduit!375

fix(main): fix request size limit to max_request_size (axum defaults 2MB)

See merge request famedly/conduit!406

Also add `.envrc` for direnv + Nix users. This makes developing locally
easier for us NixOS folks.

The flake itself will allow NixOS users to pull code directly from
Conduit's repository, making it completely trivial to stay up-to-date
with every commit.

I'd also like to add a NixOS module directly to this repository at some
point so that new configuration options will be available in the NixOS
module faster. But for now, NixOS users can simply override
`serivces.matrix-conduit.package` and get pretty much all the
functionality.

I've added myself to the `CODEOWNERS` file for the Nix files, since I am
willing to maintain this stuff. I use Conduit on NixOS so I'm personally
invested in having this work.

Lastly, `.gitignore` was updated to exclude symlinks created by `direnv`
and `nix build` and other such Nix commands.

This doesn't come without maintenance burden, however:

* The `sha256` in `flake.nix` will need to be updated whenever Conduit's
  MSRV is updated, but that should be pretty infrequent.

* `nix flake update` should be run every so often to pull in updates to
  `nixpkgs` and other flake inputs. I think downstream users can also
  override this themselves with `inputs.<name>.inputs.<name>.follows`.

* `nix flake check` should be run in CI to ensure Nix builds keep
  working.

* `nixpkgs-fmt --check $(fd '\.nix')` (or similar) should be run in CI
  to ensure style uniformity.

fix: update persy implementation after refactor

See merge request famedly/conduit!396

Raise 404 "Room not found" when changing or accessing room visibility
settings (`GET` and `PUT
/_matrix/client/r0/directory/list/room/{roomId}`).
See issue #290

update rust to avoid a cargo problem

See merge request famedly/conduit!395

Fix is_guest value on whoami for appservice users

Closes #310

See merge request famedly/conduit!401

Bump default room version to V9

See merge request famedly/conduit!400

Rejoin over federation if we are not participating

See merge request famedly/conduit!399

Fix doing restricted joins into rooms we are not participating in

See merge request famedly/conduit!398

Allows Conduit users to join restricted rooms if we are not currently participating

Rejoin room over federation if we are not participating in it; do not include invited users in participating servers calculation