Use -D warnings in all relevant CI

[BenjaminBrienen]

Objective

Fixes #17009

See: https://doc.rust-lang.org/stable/clippy/continuous_integration/index.html

Solution

Add the env

Testing

CI should start to fail, then I'll fix it.

Showcase

[alice-i-cecile]

I broadly agree with this: deny warnings is the standard practice for Rust + Bevy, and blocking CI is the best way to ensure that these are fixed and stay fixed.

[BenjaminBrienen]

An alternative direction that we could take is to deny warnings in CI except for unused imports, variables, and muts. This might help keep verbosity down while still catching important lints. If we do that though, I would expect all the cfg stuff to be removed in all existing places we already do do that. I don't like this though because I don't want irrelevant warnings when developing locally and there isn't enough granularity with allowing warnings in unchanged code.

[alice-i-cecile]

I don't like this though because I don't want irrelevant warnings when developing locally and there isn't enough granularity with allowing warnings in unchanged code.

Agreed. Half of the reason why these lints exist are to provide a better local development experience.

[mockersf]

OK to add -D warnings to CI, but I would prefer the warnings in task pool creation to be solved in a way that keep their builder for wasm and not wasm common

[BenjaminBrienen]

I can do that