Bug: We should make sure multiple rust-wraps work within a workspace

[krisbitney]

See https://discord.com/channels/796821176743362611/1084870441983803512/1145763806371401748

[krisbitney]

After researching this issue, it doesn't seem possible to support Rust workspaces without significant effort. It is not currently possible to override the behavior of cargo build.

Rust build scripts allow for preprocessing, but can not stop normal compilation (which will fail). A custom Rust target cannot be used to replace compilation with a custom polywrap build invocation, either.