test: add test case

Author: yyx990803

packages/runtime-core/__tests__/components/BaseTransition.spec.ts

@@ -1230,4 +1230,9 @@ describe('BaseTransition', () => {
       await runTestWithKeepAlive(testInOutBeforeFinish)
     })
   })
+
+  // #10719
+  test('should not error on KeepAlive w/ function children', () => {
+    expect(() => mount({}, () => () => h('div'), true)).not.toThrow()
+  })
 })