Compiler prevents adding attributes in front of {

[benadamstyles]

The compiler (v11) does not support @s.strict in the following structure:

@schema
type t = @s.strict {
  email: string,
  name: string,
}

This is expected to work at least by some library developers, see original bug report: DZakh/sury#151

[cristianoc]

This is exactly what discussed missing in the PR to support adding an attribute without "|" in a variant type declaration.
A follow-on PR would address this. Well at least the parse error.
CC @zth