Adding a `allow-unwrap-in-benches` option

[ClementTsang]

Description

Hello! Currently looking at using the clippy::unwrap_used lint setting - however, while this makes sense for our main service code, it isn't as important for tests and benchmark code. There's a setting for tests (allow-unwrap-in-tests) - would it be possible to add an equivalent for, say, code that is in a benches/ folder?

(I've noticed that the tests setting also doesn't work for tests/ (#13981), so I guess it would make sense to get that working first)

Version

rustc 1.90.0 (1159e78c4 2025-09-14)
binary: rustc
commit-hash: 1159e78c4747b02ef996e55082b704c09b970588
commit-date: 2025-09-14
host: aarch64-apple-darwin
release: 1.90.0
LLVM version: 20.1.8

Additional Labels

No response

[ClementTsang]

If needed, I would be open to helping work on this and #13981, though I may need some help.