Rust lab benchmarks do not use provided profile

[owobred]

Describe the bug
When running the rust benchmarks in /Laboratory/Rust/benchmarking, the bench profile is ignored. This means that neither the LTO nor the codegen-units used when building.

To Reproduce

1. Go to /Laboratory/Rust/benchmarking
2. Run cargo bench
3. See warning at top of output

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots / Snippets

warning: profiles for the non root package will be ignored, specify profiles at the workspace root:
package:   /home/bred/scratch/bebop/Laboratory/Rust/benchmarking/Cargo.toml
workspace: /home/bred/scratch/bebop/Laboratory/Rust/Cargo.toml

Info
Tested on 03502a9 using Ubuntu 23.10 on wsl2.
dotnet 8.0.103, rustc 1.79.0-nightly (aa1c45908 2024-04-06)

Additional context
This should probably be fixed by moving the [profile.bench] section from /Laboratory/Rust/benchmarking/Cargo.toml to /Laboratory/Rust/Cargo.toml.
This has no real effect on benchmarks, other than making bincode marginally faster when serializing.

[andrewmd5]

Thanks for reporting this. Would you mind submitting a PR with the necessary changes?

[owobred]

PR created #328.