Add WINIO ghc 9 release notes
Basic release note for GHC 9 for WinIO.
Fixes #18385 (closed) and migration guide has been updated https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.0#io-manager-winio-related-changes
Basic release note for GHC 9 for WinIO.
Fixes #18385 (closed) and migration guide has been updated https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.0#io-manager-winio-related-changes