[tlbuild] wget updates?

[Karl Berry]

wget-1.21.3 was released recently
(https://ftp.gnu.org/gnu/wget/wget-1.21.tar.gz). I guess it would be
good to update the binary on those platforms where we provide it:

wget.amd64-freebsd wget.i386-freebsd
wget.amd64-netbsd wget.i386-netbsd
wget.i386-solaris wget.x86_64-solaris
wget.x86_64-darwinlegacy
wget.x86_64-linuxmusl
wget.exe # already done, thanks Akira

But if it's a hassle to build, I don't suppose it's crucial. --thanks,karl.