/DEBUG:FASTLINK is deprecated

[AustinSchuh]

https://learn.microsoft.com/en-us/cpp/build/reference/debug-generate-debug-info?view=msvc-170

The /DEBUG:FASTLINK option is deprecated and removed starting in Visual Studio 2026. It was available in Visual Studio 2017 through Visual Studio 2022.

One of our developers says that it is slower than /DEBUG:FULL on recent Visual Studio's.

wpilibsuite/allwpilib#8517

I'll look at writing a patch, but it would be awesome to be able to control what gets used.

[trybka]

This was also reported in #488 though the context of FASTLINK being slower was missing.

I think we'd accept a patch to upgrade to FULL in newer Visual Studios?