Re-enable unused_qualifications lint

[Xylphy]

Summary
This PR re-activates the unused_qualifications lint by setting it back to warn in the lint config:

- #unused_qualifications = "warn" // TODO: fix warnings in uucore, then re-enable this lint
+ unused_qualifications = "warn"

Motivation
unused_qualifications had been commented out due to warnings in uucore. Those warnings have now been addressed, so we can restore the lint to catch future regressions.

Testing

• Verified on Linux locally.
• I haven’t tested on other platforms; CI should confirm if this passes

Notes
If CI reports platform-specific warnings or toolchain differences, I’ll follow up with fixes or adjust the lint scope as needed.

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/tail/follow-name (passes in this run but fails in the 'main' branch)

[sylvestre]

Some jobs are sad

[Xylphy]

Hahahahahahaha mhmmm, I'll push a fix in a bit

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tty/tty-eof (fails in this run but passes in the 'main' branch)

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[github-actions]

GNU testsuite comparison:

Skipping an intermittent issue tests/shuf/shuf-reservoir (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/sort/sort-stale-thread-mem (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/inotify-dir-recreate (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/bounded-memory is now passing!

[xtqqczze]

---- test_dd::test_bytes_suffix_recursive stdout ----
bin: "/home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils"
run: /home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils dd count=2Bx2 status=none
bin: "/home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils"
run: /home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils dd skip=2Bx2 status=none
bin: "/home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils"
run: /home/runner/work/coreutils/coreutils/target/aarch64-unknown-linux-gnu/debug/coreutils dd iseek=2Bx2 status=none

thread 'test_dd::test_bytes_suffix_recursive' panicked at tests/uutests/src/lib/util.rs:412:35:
called `Option::unwrap()` on a `None` value

Looks like #10442

[xtqqczze]

Overall, the changes look fine to me, but since in some cases the qualification might have been added to improve readability, we should consider those instances carefully.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/shuf/shuf-reservoir (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/sort/sort-stale-thread-mem (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)
Note: The gnu test tests/printf/printf-surprise is now being skipped but was previously passing.

[xtqqczze]

broke CI:

  error: unnecessary qualification
     --> src\uu\numfmt\src\numfmt.rs:344:18
      |
  344 |     Command::new(uucore::util_name())
      |                  ^^^^^^^^^^^^^^^^^
      |
      = note: `-D unused-qualifications` implied by `-D warnings`
      = help: to override `-D warnings` add `#[allow(unused_qualifications)]`

[Xylphy]

Yes, apparently this PR was considered stale and was merged. I'll follow up a fix

[xtqqczze]

@sylvestre Is it time to use a merge queue to prevent this kind of issue?

[sylvestre]

it isn't a big deal :)