7.15.0

Update to FSAC 0.66.1. Check out the release notes for more details.
Updated the F# syntax grammar to pick up fixes for backticked namespace and module names, let struct syntax highlights, and customer operators/doc comments. (Thanks @dawedawe and @MangelMaxime!)
Added a deprecation message to FSharp.inlayHints.enabled in favor of editor.inlayHints.enabled.