fix clippy warnings:

[matthiaskrgr]

manual_range_contains
needless_lifetimes

[rust-highfive]

r? @ehuss

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[est31]

You could use matches! here as well.

[ehuss]

Thanks! I appreciate trying to make small code cleanups (I post them myself sometimes!). However, I'm not sure either of these changes really makes the code more readable for me. The contains change seems to express the same thing, just in a different way. The "needless lifetimes" doesn't seem so needless, since it still needs to include '_, and now it is not clear what that '_ lifetime is referring to. I somehow now need to run the lifetime inference algorithm in my head to know what it means, which is not something I'm capable of doing.

I won't oppose if someone else on the team wants to merge this if they think it is an improvement, but I personally would prefer to keep these as they were.