Fixes some Fantomas errors where it was using an old
method which no longer exists.

**Fantomas**: Error occurred: Method not found:
Microsoft.FSharp.Control.FSharpAsync`1<FSharp.Compiler.SourceCodeServices.FSharpParseFileResults> FSharp.Compiler.SourceCodeServices.FSharpChecker.ParseFile(string,string,FSharp.Compiler.SourceCodeServices.FSharpParsingOptions,Microsoft.FSharp.Core.FSharpOption`1<string>)

This version of Fantomas supports
FSharp.CompilerService 30.0