Rollup merge of #143031 - mati865:push-mutywntmvomx, r=Mark-Simulacrum

Add windows-gnullvm hosts to the manifest

I made a mistake testing rust-lang/rust#140772 only with `rustup-toolchain-install-master` which doesn't care about the manifests.

This means windows-gnullvm self-hosting will have to wait one more release, unless this change is backported to beta and a new beta release is made, which doesn't seem worth the trouble.

Author: matthiaskrgr