Fix Rust builds when sanitizers are enabled

[emmatyping]

We should fix Rust builds when sanitizers are enabled

• asan - Works as-is
• tsan - example failure: https://github.com/Rust-for-CPython/cpython/actions/runs/22603598706/job/65491451673
• ubsan - not supported by Rust, so we should do a normal Rust build when ubsan is enabled

There's an additional open question about whether Rust's sanitzer support works with gcc's (I expect not?), but it'd be good to follow up on that.

[FFY00]

As mentioned on the PR, the address sanitizer should be okay. We have the same issue with C++ in external dependencies already as described in the Rust docs you linked. Have you encountered any specific issues when running with the address sanitizer?

[emmatyping]

@FFY00

As mentioned on the PR, the address sanitizer should be okay.

Yup, seems like it is working now!

We have the same issue with C++ in external dependencies already as described in the Rust docs you linked.

Yeah, probably just something we'll need to toggle in the Rust builds.

[emmatyping]

Fixed in #29

Eventually we will want to modify the build to run with identical LLVM versions for Rust and clang, but that can wait.