Handle methods that have opt args but no kws

Closes PR 14726

pkgs/typed-racket-pkgs/typed-racket-lib/typed-racket/typecheck/check-class-unit.rkt

@@ -1421,7 +1421,7 @@
                                                        core-body ...)))
                            method-body ...)])
              m)
-           kw:kw-lambda^)
+           (~or kw:kw-lambda^ opt:opt-lambda^))
      (do-register #'self-param #'meth-name)]
     ;; case-lambda methods
     [(let-values ([(meth-name:id)

pkgs/typed-racket-pkgs/typed-racket-test/tests/typed-racket/unit-tests/class-tests.rkt

@@ -1493,4 +1493,16 @@
    [tc-err (make-object (ann object% ClassTop))
            #:msg #rx"cannot instantiate.*ClassTop"]
    [tc-err (make-object 3)
-           #:msg #rx"value of a non-class type"]))
+           #:msg #rx"value of a non-class type"]
+   ;; PR 14726
+   ;; test opt-arg but non-keyword method
+   [tc-e (let ()
+           (define-type-alias A%
+             (Class [foo (->* [Integer] Void)]))
+           (: a% A%)
+           (define a%
+             (class object%
+               (super-new)
+               (define/public (foo [i #f]) (void))))
+           (new a%))
+         (-object #:method ([foo (t:-> -Integer -Void)]))]))