Be more picky about Opaque type parsing

Closes PR 14122

pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/private/parse-type.rkt

@@ -285,7 +285,7 @@
        (-val (syntax->datum #'t))]
       [((~and kw t:All) . rest)
        (parse-all-type stx)]
-      [((~and kw t:Opaque) p?)
+      [((~and kw t:Opaque) p?:id)
        (add-disappeared-use #'kw)
        (make-Opaque #'p?)]
       [((~and kw t:Parameter) t)

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/parse-type-tests.rkt

@@ -137,6 +137,9 @@
    [(Integer -> (All (X) (X -> X)))
     (t:-> -Integer (-poly (x) (t:-> x x)))]
 
+   [(Opaque foo?) (make-Opaque #'foo?)]
+   ;; PR 14122
+   [FAIL (Opaque 3)]
    ))
 
 ;; FIXME - add tests for parse-values-type, parse-tc-results