Publish to Bazel Central Registry

[dtolnay]

With a suitable MODULE.bazel, we should be able to make a rust_cxx_bridge rule easily available for Bzlmod users.

https://github.com/bazelbuild/bazel-central-registry
https://bazel.build/build/bzlmod

For now this is blocked on Bzlmod support in bazelbuild/rules_rust#1493.

[tel]

Given #1294 has merged, is it possible that this will get published to the central registry?

I've been trying to get this working using git_override and struggling a bit, though I'm pretty new to Bazel. I'm curious if this is an intended way to use cxx in a Bazel project.

[louwers]

@tel I was able to use cxx with git_override like this: https://github.com/maplibre/maplibre-native/blob/527e70b6fa7f2ff1d3c7546f1773c5404b8a3733/MODULE.bazel#L65-L70