Bump libc & fix clippy errors on FreeBSD

[cakebaker]

This PR bumps libc from 0.2.175 to 0.2.176 and fixes two clippy errors from the useless_conversion lint on FreeBSD (see https://github.com/uutils/coreutils/actions/runs/17946395896/job/51033759647?pr=8717#step:5:4493).

[codspeed-hq]

CodSpeed Performance Report

Merging #8722 will not alter performance

_{Comparing cakebaker:bump_libc (2480842) with main (5287738)}

Summary

✅ 45 untouched
⏩ 1 skipped¹

Footnotes

1. 1 benchmark was skipped, so the baseline result was used instead. If it was deleted from the codebase, click here and archive it to remove it from the performance reports. ↩

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/misc/stdbuf (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/misc/tee (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/timeout/timeout (fails in this run but passes in the 'main' branch)