Rust build image needs updating

There are quite a number of rust projects that are not building because they depend on the serde crate. But the serde crate requires a more up to date version of rustc (as the current version hasn't been updated since febuary). This is the error across many repositories that have failing builds.

```
add `#![feature(diagnostic_namespace)]` to the crate attributes to enable
Step #3 - "compile-libfuzzer-address-x86_64":  = note: this compiler was built on 2024-02-11; consider upgrading it if it is out of date
Step #3 - "compile-libfuzzer-address-x86_64":
Step #3 - "compile-libfuzzer-address-x86_64": For more information about this error, try `rustc --explain E0658`.
Step #3 - "compile-libfuzzer-address-x86_64": The following warnings were emitted during compilation:
```

So far I've fixed two rounds of builds by simple updating rustc in the project specific Dockerfile e.g.
- https://github.com/google/oss-fuzz/pull/12409
- https://github.com/google/oss-fuzz/pull/12404

Review the project-specific Dockerfiles and the Rust compiler versions used there; compare the update patterns in PRs #12409 and #12404. Confirm completion by rebuilding the affected serde-dependent projects and verifying that the reported rustc E0658 failures no longer occur.

Written by the indexing model from the issue text.