clippy: fix warnings with Rust 1.95.0

[cakebaker]

This PR fixes warnings from the collapsible_match and unnecessary_sort_by lints.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 19.20%. Comparing base (c1801fd) to head (e059828).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
src/uu/pgrep/src/process_matcher.rs	0.00%	2 Missing ⚠️
src/uu/pmap/src/smaps_format_parser.rs	0.00%	2 Missing ⚠️
src/uu/ps/src/sorting.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #679   +/-   ##
=======================================
  Coverage   19.20%   19.20%           
=======================================
  Files          68       68           
  Lines       10155    10153    -2     
  Branches      546      546           
=======================================
  Hits         1950     1950           
+ Misses       8205     8203    -2     

Flag	Coverage Δ
macos_latest	6.74% <0.00%> (+<0.01%)	⬆️
ubuntu_latest	19.56% <0.00%> (+<0.01%)	⬆️
windows_latest	0.02% <0.00%> (+<0.01%)	⬆️

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[cakebaker]

I merged this PR myself to get the CI back to green.