Don't recurse into inner functions during asyncjs transform (#23036)

Closes #13341

lib/js/asyncjs.nim

@@ -90,6 +90,8 @@ proc replaceReturn(node: var NimNode) =
       node[z] = nnkReturnStmt.newTree(value)
     elif son.kind == nnkAsgn and son[0].kind == nnkIdent and $son[0] == "result":
       node[z] = nnkAsgn.newTree(son[0], nnkCall.newTree(jsResolve, son[1]))
+    elif son.kind in RoutineNodes:
+      discard
     else:
       replaceReturn(son)
     inc z

tests/js/tasyncjs.nim

@@ -99,4 +99,9 @@ block asyncPragmaInType:
   proc foo() {.async.} = discard
   var x: Handler = foo
 
+block: # 13341
+  proc f {.async.} =
+    proc g: int =
+      result = 123
+
 discard main()