Disable Whole Program Optimization on MSVC

[azeey]

🦟 Bug fix

• Needs Make Whole Program Optimization (WPO) optional on MSVC gz-cmake#532

Summary

This leverages the new GZ_MSVC_WPO option in gz-cmake to globally disable Whole Program Optimization (which removes /GL and /LTCG) to significantly speed up Windows build times.

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the fix (as needed)
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• Updated Bazel files (if adding new files). Created an issue otherwise.
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Generated-By: Gemini 3.1 Pro

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