[gmp] Feature fat couldn't build on Windows

[LilyWangLL]

Fixes #27957, gmp[fat] can't build on windows because the following error, so change it supports to disable windows build temporarily.

Thanks fkonvick's investigation and dg0yt's help ♥.

C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4686): error C2071: 'preinv_mod_1': illegal storage classlibtool: compile:  .././../src/v6.2.1-0c723d4b6f.clean/mpn/m4-ccas --m4=m4 clang.exe -DHAVE_CONFIG_H -I. -I.././../src/v6.2.1-0c723d4b6f.clean/mpn -I.. -D__GMP_WITHIN_GMP -I.././../src/v6.2.1-0c723d4b6f.clean -DOPERATION_x86_64_mod_34lsub1 -DWIN32 -D_WINDOWS -D_DEBUG -c --target=x86_64-pc-windows-msvc x86_64_mod_34lsub1.asm  -DDLL_EXPORT -DPIC -o .libs/x86_64_mod_34lsub1.obj

C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4687): error C2071: 'redc_1': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4688): error C2071: 'redc_2': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4689): error C2071: 'rshift': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4690): error C2071: 'sqr_basecase': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4691): error C2071: 'sub_n': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4692): error C2071: 'sublsh1_n': illegal storage class
C:\BUILD\vcpkg\buildtrees\gmp\src\v6.2.1-0c723d4b6f.clean\gmp-impl.h(4693): error C2071: 'submul_1': illegal storage class

• Changes comply with the maintainer guide
• SHA512s are updated for each updated download
• The "supports" clause reflects platforms that may be fixed by this new version
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.