experimental C API: Fix compilation failure in Windows.

The functions added in
https://github.com/tensorflow/tensorflow/commit/be917027e37c5e8f21f6ba07f24bdbf072cf6dfd
are temporary, and their existence breaks compilation in MSVC because of
https://docs.microsoft.com/en-us/cpp/c-language/maximum-string-length
and
https://docs.microsoft.com/en-us/cpp/error-messages/compiler-errors-1/compiler-error-c2026

So just disabling it in Windows for now.

PiperOrigin-RevId: 192391164