cabal init -i: add the GHC2021 language option (fix #8265)

[cabal.git] / changelog.d / remove-experimental-multilibs-warning

synopsis: Unmarked "visibility: public" and "build-depends: pkg:lib" syntaxes as experimental, allowing Hackage upload of packages exposing or using multiple public libraries
packages: Cabal
prs: #8089
issues: #6801 #7286