du: do not panic on a non-UTF-8 name in the --exclude check

[leeewee]

Fixes #12769

du's regular (non-safe) traversal — used whenever -L/--dereference is given, and always on non-Linux — matched --exclude patterns against entry.file_name().into_string().unwrap(). OsString::into_string() returns Err for any non-UTF-8 entry name, so the .unwrap() aborted the process:

$ mkdir -p duex/sub
$ python3 -c "import os; os.mkdir(b'duex/sub/\xff\xfedir')"
$ du -L --exclude='zzz' duex
thread 'main' panicked at src/uu/du/src/du.rs:656:89:
called `Result::unwrap()` on an `Err` value: "\xFF\xFEdir"
$ echo $?
134

GNU lists the directory and exits 0. This uses to_string_lossy() instead — matching the sibling this_stat.path.to_string_lossy() already on the line above (and the identical exclude check in the safe traversal) — so a non-UTF-8 name is handled gracefully:

$ du -L --exclude='zzz' duex ; echo $?
...
0

Added a Unix-gated regression test (test_du_exclude_non_utf8_name).

[codspeed-hq]

Merging this PR will improve performance by 3.45%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
✅ 322 untouched benchmarks
⏩ 46 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	single_date_now	85.5 µs	82.7 µs	+3.45%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing leeewee:du-fix-exclude-non-utf8 (c86ab87) with main (220a8ec)}

Footnotes

1. 46 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/tail-n0f (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/timeout/timeout-group (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/cut/bounded-memory (passes in this run but fails in the 'main' branch)
Skipping an intermittent issue tests/tail/retry (passes in this run but fails in the 'main' branch)