Fix view transitions setting values not being saved

[Soean]

Summary

The plvt_sanitize_setting() function of the view transitions plugin sanitizes the default values, not the input values. Currently, the new input values of the selectors are not saved. This PR fixes the problem.

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Co-authored-by: Soean <soean@git.wordpress.org>
Co-authored-by: felixarntz <flixos90@git.wordpress.org>

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 68.06%. Comparing base (05444d4) to head (8f3679f).
Report is 3 commits behind head on trunk.

Files with missing lines	Patch %	Lines
plugins/view-transitions/includes/settings.php	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            trunk    #2036   +/-   ##
=======================================
  Coverage   68.06%   68.06%           
=======================================
  Files          92       92           
  Lines        7626     7626           
=======================================
  Hits         5191     5191           
  Misses       2435     2435           

Flag	Coverage Δ
multisite	68.06% <0.00%> (ø)
single	37.03% <0.00%> (ø)

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[felixarntz]

Yikes! This must have broken at some point late during #2025, because I had tested it before and confirmed it working.

Thanks for catching that @Soean!

This reminds me... it's an early release, but we should really add unit test coverage. :)

Since this is a rather critical bug/limitation, I'll publish this fix in a 1.0.1.