Fix warnings due to changes on Unity 6.4+

[thomas-tu]

DO NOT FORGET TO INCLUDE A CHANGELOG ENTRY

Purpose of this PR

This PR bring mandatory changes due to recent updates on U6.5.

[Brief summary of the changes in this PR.]

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Jira:

Comments to Reviewers

[List known issues, planned work, provide any extra context for your code.]

[u-pr]

PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

⏱️ Estimated effort to review: 1 🔵⚪⚪⚪⚪ The PR contains straightforward preprocessor directive updates to accommodate Unity 6000.5 API changes.

🏅 Score: 100 The changes cleanly address the Unity 6.5 warnings using proper compiler directives, maintaining backward compatibility without introducing complexity.

🧪 PR contains tests

🔒 No security concerns identified

⚡ No major issues detected

Update review

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[u-pr]

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[codecov-github-com]

Codecov Report

All modified and coverable lines are covered by tests ✅

@@           Coverage Diff           @@
##           master     #655   +/-   ##
=======================================
  Coverage   36.05%   36.06%           
=======================================
  Files         277      277           
  Lines       34909    34910    +1     
=======================================
+ Hits        12588    12589    +1     
  Misses      22321    22321           

Files with missing lines	Coverage Δ
Editor/EditorCore/EditorUtility.cs	49.75% <100.00%> (+0.24%)	⬆️

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