fix(mp-xhs): 修复 API requestPayment 调用不生效的 Bug (question/194812)

[chouchouji]

小红书官方文档

https://miniapp.xiaohongshu.com/doc/DC411188

[Otto-J]

补充 initProvider 保证用户的一套套代码可以运行在多端，代码不变，有可能用户会根据 provider 的返回值做判断

[github-actions]

Size report

Path	Size
packages/size-check/dist/size-check.es.js	47.19 KB (0%)
packages/size-check/dist/style.css	2.82 KB (0%)
packages/uni-app/dist/uni-app.es.js	2.5 KB (0%)
packages/uni-h5-vue/dist/vue.runtime.esm.js	76.41 KB (0%)
packages/uni-mp-vue/dist/vue.runtime.esm.js	43.22 KB (0%)
packages/uni-mp-alipay/dist/uni.api.esm.js	14.83 KB (0%)
packages/uni-mp-alipay/dist/uni.mp.esm.js	7.99 KB (0%)
packages/uni-mp-baidu/dist/uni.api.esm.js	11.33 KB (0%)
packages/uni-mp-baidu/dist/uni.mp.esm.js	9.68 KB (0%)
packages/uni-mp-qq/dist/uni.api.esm.js	10.65 KB (0%)
packages/uni-mp-qq/dist/uni.mp.esm.js	7.6 KB (0%)
packages/uni-mp-toutiao/dist/uni.api.esm.js	10.47 KB (0%)
packages/uni-mp-toutiao/dist/uni.mp.esm.js	9.42 KB (0%)
packages/uni-mp-weixin/dist/uni.api.esm.js	11.65 KB (0%)
packages/uni-mp-weixin/dist/uni.mp.esm.js	8.16 KB (0%)
packages/uni-quickapp-webview/dist/uni.api.esm.js	10.6 KB (0%)
packages/uni-quickapp-webview/dist/uni.mp.esm.js	8.16 KB (0%)