message: add missing `HasQueryGroup`
diff: @@ -379,6 +379,7 @@ pub(crate) fn query_group(args: TokenStream, input: TokenStream) -> TokenStream
  impl<DB> salsa::plumbing::QueryFunction<DB> for #qt
  where
  DB: #trait_name,
  + DB: salsa::plumbing::HasQueryGroup<#group_struct>,
  DB: salsa::Database,
  {
  fn execute(db: &DB, #key_pattern: <Self as salsa::Query<DB>>::Key)
  