`ruff` is currently built from source in the nix flake, slowing down dev environment creation and requiring a moving rust version

This issue has been migrated from [#15939](https://github.com/matrix-org/synapse/issues/15939).

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We have a [`flake.nix`](https://github.com/matrix-org/synapse/blob/20ae617d1417f8dd52e20b3a20cb01b4c2fd87c9/flake.nix) file which can be used to create a full development environment for Synapse, including python and native dependencies and things like postgres and redis.

The development environment will automatically keep its python environment up to date with `poetry` using the versions defined in `pyproject.yaml`. One of those python package is [`ruff`](https://github.com/charliermarsh/ruff), which we use as a linter.

`ruff` ships a rust binary, which is dynamically linked against either glibc or musl. As such, `ruff` expects `glibc` or `muslc` headers to exist at a certain location on your Linux box. Due to [the way NixOS works](https://nixos.wiki/wiki/Packaging/Binaries#The_Dynamic_Loader), these do not exist under the expected path, causing any `ruff` binaries we download from PyPI to fail to execute.

Thus, we have the following workaround in `flake.nix`, which forces `ruff` to be compiled on the local system:

https://github.com/matrix-org/synapse/blob/20ae617d1417f8dd52e20b3a20cb01b4c2fd87c9/flake.nix#L115-L122

This works, but is slow (as you need to compile a rust binary) and forces the development environment to maintain a rust version which is high enough to compile `ruff` (which unfortunately is almost always the latest stable. I found today that while we only require rust `1.60.0` in Synapse, the version of `ruff` we have specified in our `pyproject.toml` requires rust `1.70.0`.

The ideal solution here is for `ruff` to provide statically linked binaries to download. This has been discussed in https://github.com/astral-sh/ruff/issues/1699, and they are up for it if it does not compromise performance (or alternatively they could provide a `ruff-static` PyPI package.

Until then, we can't do much on this side.