lint: fix lints of new Rust version

[Krysztal112233]

Fix new lints of clippy.

[Krysztal112233]

Heres the action's log about failure, but it doesn't happen on my Debian testing.

   error: unused import: `set_symlink_file_times`
   --> tests/by-util/test_touch.rs:8:16
    |
  8 | use filetime::{set_symlink_file_times, FileTime};
    |                ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D unused-imports` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(unused_imports)]`
  
  error: could not compile `coreutils` (test "tests") due to 1 previous error
  Error: ERROR: `cargo clippy`: unused import: `set_symlink_file_times` (file:'tests/by-util/test_touch.rs', line:8)
       Removed 2866 files, 693.6MiB total
  exec shell: bash run.sh showDebugInfo

It only happend on freebsd target I think.

[Krysztal112233]

coreutils::tests test_sort::test_output_is_input's failure may not caused by this PR after my check.

[sylvestre]

could you please fix the windows clippy warnings too as you are working on it ?
https://github.com/uutils/coreutils/actions/runs/8378663843/job/22943749149?pr=6102

[Krysztal112233]

could you please fix the windows clippy warnings too as you are working on it ?
https://github.com/uutils/coreutils/actions/runs/8378663843/job/22943749149?pr=6102

I'll fix it later

[Krysztal112233]

Here's a lots of denied warnings about clippy::cognitive_complexity

 error: the function has a cognitive complexity of (14/10)
   --> tests\common\random.rs:254:8
    |
254 |     fn test_random_string_generate_with_delimiter_should_not_end_with_delimiter() {
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: you could split it up into multiple smaller functions
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity

and the longest is 71

error: the function has a cognitive complexity of (71/24)
   --> tests/by-util/test_env.rs:448:4
    |
448 | fn test_env_with_gnu_reference_parsing_errors() {
    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: you could split it up into multiple smaller functions
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity
    = note: `-D clippy::cognitive-complexity` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::cognitive_complexity)]`

There are two solutions

• Change the configuration of cognitive-complexity-threshold in .clippy.toml from 10 to 71, avoid changing the unit testing function name
• Change from 10 to 24 and rename only one unit testing function name

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)

[Krysztal112233]

Here's a lots of denied warnings about clippy::cognitive_complexity

 error: the function has a cognitive complexity of (14/10)
   --> tests\common\random.rs:254:8
    |
254 |     fn test_random_string_generate_with_delimiter_should_not_end_with_delimiter() {
    |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: you could split it up into multiple smaller functions
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity

and the longest is 71

error: the function has a cognitive complexity of (71/24)
   --> tests/by-util/test_env.rs:448:4
    |
448 | fn test_env_with_gnu_reference_parsing_errors() {
    |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: you could split it up into multiple smaller functions
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#cognitive_complexity
    = note: `-D clippy::cognitive-complexity` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::cognitive_complexity)]`

There are two solutions

* Change the configuration of `cognitive-complexity-threshold` in `.clippy.toml` from `10` to `71`, avoid changing the unit testing function name

* Change from `10` to `24` and rename only one unit testing function name

I think add #[allow(clippy::cognitive_complexity)] would be better because of the clap made a good example.

So I'll add #[allow(clippy::cognitive_complexity)] to resolve the issues.

[tertsdiepraam]

Looking good. Can be merged in my opinion, but I do have a few questions.

[tertsdiepraam]

Wait this was super low all this time??? No wonder it was so annoying. Let's just remove this line; the default value is 25 according to the documentation

[tertsdiepraam]

@sylvestre I see that you introduced the lower value. I think 10 is a bit too low, but I'm happy to compromise on something inbetween as well. I think the problem with 10 is that it's a good hint that a function is too complex, but too restrictive to enforce.

[sylvestre]

sure, it was to identify too long/complex functions. I am happy where we are now with 25
thanks