Adjust around advice to work in Emacs < 30

The implementation added in the previous commit requires Emacs 30.
This commit adds a kludge that is necessary to make it work in older
versions.  Also see bug#61179.

Author: tarsius

lisp/transient.el

@@ -2194,32 +2194,37 @@ value.  Otherwise return CHILDREN as is."
        ,@body)))
 
 (defun transient--wrap-command ()
-  (letrec ((prefix transient--prefix)
-           (suffix this-command)
-           (advice (lambda (fn &rest args)
-                     (interactive
-                      (lambda (spec)
-                        (let ((abort t))
-                          (unwind-protect
-	                      (prog1 (advice-eval-interactive-spec spec)
-	                        (setq abort nil))
-	                    (when abort
-                              (when-let ((unwind (oref prefix unwind-suffix)))
-                                (transient--debug 'unwind-interactive)
-                                (funcall unwind suffix))
-                              (if (symbolp suffix)
-                                  (advice-remove suffix advice)
-                                (remove-function suffix advice))
-                              (oset prefix unwind-suffix nil))))))
-                     (unwind-protect
-                         (apply fn args)
-                       (when-let ((unwind (oref prefix unwind-suffix)))
-                         (transient--debug 'unwind-command)
-                         (funcall unwind suffix))
-                       (if (symbolp suffix)
-                           (advice-remove suffix advice)
-                         (remove-function suffix advice))
-                       (oset prefix unwind-suffix nil)))))
+  (let* ((prefix transient--prefix)
+         (suffix this-command)
+         (advice nil)
+         (advice-interactive
+          (lambda (spec)
+            (let ((abort t))
+              (unwind-protect
+	          (prog1 (advice-eval-interactive-spec spec)
+	            (setq abort nil))
+	        (when abort
+                  (when-let ((unwind (oref prefix unwind-suffix)))
+                    (transient--debug 'unwind-interactive)
+                    (funcall unwind suffix))
+                  (if (symbolp suffix)
+                      (advice-remove suffix advice)
+                    (remove-function suffix advice))
+                  (oset prefix unwind-suffix nil))))))
+         (advice-body
+          (lambda (fn &rest args)
+            (unwind-protect
+                (apply fn args)
+              (when-let ((unwind (oref prefix unwind-suffix)))
+                (transient--debug 'unwind-command)
+                (funcall unwind suffix))
+              (if (symbolp suffix)
+                  (advice-remove suffix advice)
+                (remove-function suffix advice))
+              (oset prefix unwind-suffix nil)))))
+    (setq advice `(lambda (fn &rest args)
+                    (interactive ,advice-interactive)
+                    (apply ',advice-body fn args)))
     (if (symbolp suffix)
         (advice-add suffix :around advice '((depth . -99)))
       (add-function :around (var suffix) advice '((depth . -99))))))