Version bump

[mati865]

Related PR: rust-lang/rust#51425

//! min_version.txt is in the repo but also in the .gitignore to
//! make sure that it is not updated manually by accident. Only CI
//! should update that file.

I'm not quite sure about CI part.

[oli-obk]

Yea... the CI part isn't happening yet, so you'd need to run rustc -vV > min_version.txt manually.

I'll do that locally before publishing.

Thanks for taking care of the entire update process! This makes it much easier for me

[mati865]

It could be mentioned in PUBLISH.md or even done by pre_publish.sh until CI part is done.
Just in case somebody else would need to publish.