Wrong GCC version in Windows toolchain name

[matsobdev]

riscv-toolchain-14-x64-win.zip sounds like GCC 14.something.something, but in fact it is 13.2.0.

[will-v-pi]

Yes, that is correct - the Windows and x86_64 macOS toolchains are both taken from here and merely have our standard library copied in, so are GCC 13. We can remove the version from the filename if that is causing confusion.