Upstream: `Build: Ambiguous call to isfinite for MSVC 17.11`

[illusion0001]

Fixes build for new MSVC versions.

D:\a\goo-blender\goo-blender\intern\cycles\scene\image.cpp(637,14): error C2668: 'ccl::`anonymous-namespace'::isfinite': ambiguous call to overloaded function [D:\a\goo-blender\build_windows_x64_vc17_Release\intern\cycles\scene\cycles_scene.vcxproj]
    D:\a\goo-blender\goo-blender\intern\cycles\scene\image.cpp(40,6):
    could be 'bool ccl::`anonymous-namespace'::isfinite(uint16_t)'
    D:\a\goo-blender\goo-blender\intern\cycles\scene\image.cpp(36,6):
    or       'bool ccl::`anonymous-namespace'::isfinite(ccl::half)'
    D:\a\goo-blender\goo-blender\intern\cycles\scene\image.cpp(32,6):
    or       'bool ccl::`anonymous-namespace'::isfinite(ccl::uchar)'

Original commit comment:

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Build: Ambiguous call to isfinite for MSVC 17.11

Overload resolution must have changed and is causing issues for one particular code path attempting to use isfinite(ccl::uchar). Compiler output attached.

It turns out that the code in question can be simplified to just remove the ambiguity because only the float codepath wants to check for finite values.

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Reduced repro: https://godbolt.org/z/YWz3Yc3x8 Pull Request: https://projects.blender.org/blender/blender/pulls/125348