Rollup merge of #141456 - Urgau:check-cfg-version-pred, r=jieyouxu

Suggest correct `version("..")` predicate syntax in check-cfg

This PR specialize the `unexpected_cfgs` lint diagnostic to suggest correct `version("..")` predicate syntax when providing the key-value one, eg. `version = "1.27"`.

Fixes rust-lang/rust#141440
r? ``@jieyouxu``

Author: matthiaskrgr