Syntax highlighting is broken for F#.Editor

[psfinaki]

In the current main, any file in this project seems to have the issue, e.g. SignatureHelp:

Compare to VS GA:

[abelbraaksma]

Is it possibly related to this other regression? #14124

[vzarytovskii]

Is it possibly related to this other regression? #14124

Looks unrelated, will look at it shortly.

[vzarytovskii]

Fixed by #14189