cmake: Support setting the dynamic linker

[erikarvstedt]

This allows building Zig with the correct dynamic linker in environments where the auto detection mechanism fails, like in Nix dev shells.

(--host-dynamic-linker has been in std.Build for a while now, but it only recently became available to cmake via a zig1.wasm update.)

[andrewrk]

Please see #19684. I think this functionality was a mistake. Distros will need to use the -Ddynamic-linker=foo option created by standardTargetOptions for zig projects.