perf: Don't rechunk aligned chunks in owned_binary_chunk_align

[ritchie46]

We can follow up with a alignment strategy that never rechunks. This fixes the completely unneeded case.

[codecov]

Codecov Report

Attention: Patch coverage is 7.14286% with 13 lines in your changes missing coverage. Please review.

Project coverage is 80.33%. Comparing base (6c4835e) to head (f4bd051).
Report is 22 commits behind head on main.

Files	Patch %	Lines
crates/polars-core/src/utils/mod.rs	7.14%	13 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #18314      +/-   ##
==========================================
- Coverage   80.35%   80.33%   -0.02%     
==========================================
  Files        1501     1501              
  Lines      199222   199236      +14     
  Branches     2837     2837              
==========================================
- Hits       160083   160062      -21     
- Misses      38613    38648      +35     
  Partials      526      526              

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