ci: use -pcoreutils when running clippy

[cakebaker]

While looking at #6246 I wondered why those clippy warnings were not caught by our CI. The reason is probably that ${{ matrix.job.cargo-options }} is never defined and so I replaced it with ${{ steps.vars.outputs.CARGO_FEATURES_OPTION }}. I couldn't figure out the reason and my two attempts to make the CI fail on those warnings failed. And so this PR is just about removing the undefined ${{ matrix.job.cargo-options }}. It looks like the reason is that we select the utils for the specific platform and then run clippy on those packages (which don't contain the tests). By running clippy on the coreutils package with the --features flag, the tests are also checked by clippy.

[cakebaker]

Changes since last push:

• changed ${{ steps.vars.outputs.CARGO_FEATURES_OPTION }} to --all-features as the original approach didn't work

[cakebaker]

Changes since last push:

• removed --all-features

[cakebaker]

Changes since last push:

• removed unused CARGO_FEATURES_OPTION from style_format job
• used --features ${{ matrix.job.features }} -pcoreutils instead of ${{ steps.vars.outputs.CARGO_UTILITY_LIST_OPTIONS }} when running clippy
• removed code used to set CARGO_UTILITY_LIST_OPTIONS

[cakebaker]

Changes since last push:

• fixed warnings from the redundant_clone lint

[cakebaker]

Changes since last push:

• moved unit tests from tests/by_util/test_env.rs to src/uu/env/src/env.rs
• fixed the fixes from the previous push

[cakebaker]

Changes since last push:

• fixed "the borrowed expression implements the required traits" warnings in the env tests introduced with the previous push

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/cp/same-file. tests/cp/same-file is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/cp/cross-dev-symlink. tests/cp/cross-dev-symlink is passing on 'main'. Maybe you have to rebase?

[BenWiederhake]

Does what it says on the tin, and evidently you "tested" it by finding actual problems in the code. Yay! :)

Do you know why the Windows CI fails? This doesn't look like a flake:

$ cargo nextest run --profile ci --hide-progress-bar --features=windows -p uucore -p coreutils
<SNIP downloading and compiling>
   Compiling rstest v0.19.0
   Compiling unindent v0.2.1
   Compiling hex-literal v0.4.1
    Finished `test` profile [unoptimized + debuginfo] target(s) in 1m 56s
error: creating test list failed

Caused by:
  for `coreutils::bin/coreutils`, command `'D:\a\coreutils\coreutils\target\debug\deps\coreutils-08f81a256ac17834.exe' --list --format terse` exited with code 0xc0000135: The specified module could not be found. (os error 126)
--- stdout:

--- stderr:

---
Error: Process completed with exit code 1.

[cakebaker]

@BenWiederhake it looks like it was a temporary issue

[BenWiederhake]

Looks still good 👍