Replace fxhash crate with rustc-hash

### Aircraft Version

Stable

### Description

The [fxhash](https://github.com/cbreeden/fxhash) crate isn't maintained anymore (https://osv.dev/vulnerability/RUSTSEC-2025-0057) and a possible replacement is [rustc-hash](https://github.com/rust-lang/rustc-hash).

### References (optional)

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### Additional info (optional)

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### Discord Username (optional)

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