Only add dev dependencies to the dependency list of dev targets

[Liamolucko]

Fixes #9574
Fixes #11410

rust-analyzer already counts all of the different targets of a crate as different crates, so it was pretty easy to just exclude dev dependencies from the dependency lists of targets other than test, dev and bench when ingesting cargo metadata's output. A similar thing is already done for build dependencies.

It's possible there might be something I'm missing here, since this is quite a long-standing issue which I expected to be much more complicated to solve; but, this seems to work. The circular dependency errors that rust-analyzer used to throw on wasm-bindgen went away after switching to this patched version.

[Veykril]

I don't think this works, because we analyze library targets with their tests where the test code can rely on dev-dependencies. A quick check on the impact of the analysis stats from this also seems to show this:
Baseline:

❯ cargo run --release -p rust-analyzer -q analysis-stats --memory-usage .
Database loaded:     2.38s, 217mb (metadata 279.34ms, 21mb; build 1.55s, 412kb)
  crates: 44, mods: 907, decls: 19232, fns: 14376
Item Collection:     14.20s, 471mb
  exprs: 409952, ??ty: 69 (0%), ?ty: 141 (0%), !ty: 1
Inference:           45.32s, 732mb
Total:               59.52s, 1203mb

This PR:

❯ cargo run --release -p rust-analyzer -q analysis-stats --memory-usage .
Database loaded:     1.15s, 217mb (metadata 294.54ms, 21mb; build 292.44ms, 388kb)
  crates: 44, mods: 907, decls: 19231, fns: 14376
Item Collection:     14.30s, 471mb
  exprs: 391236, ??ty: 2641 (0%), ?ty: 491 (0%), !ty: 6
Inference:           41.19s, 673mb
Total:               55.49s, 1144mb

Note the increase of unknown types (??ty).

[Veykril]

I closed the linked issues (and some others) in favor of #14167, to have a more concrete tracking issue about this. In general in one of the related issues the proper fix was described which is now noted down in that issue.

[Liamolucko]

I tried to follow the suggestion in #14167 to treat lib crates compiled for testing separately from their normal versions, but it doesn't work very well, as rust-analyzer doesn't seem to be designed to have the same file be part of multiple crates right now. Sections with #[cfg(test)] are greyed out but still have diagnostics, the little 'run test' code lenses aren't showing up because the code that produces them is only checking the first crate in the list which isn't the test version, and probably other things that I haven't noticed.

I don't think I know enough about rust-analyzer to be the one who gets this working properly, so I'm going to close this here.

[Veykril]

Thanks for having looked into it though, it's still appreciated :)