fix(wechatpay): 修复支付通知数据解析错误

- 修正了解析请求体数据时使用的变量错误
- 确保从请求中正确获取并解码 inBody 数据
- 避免因变量名错误导致的数据解析失败问题

src/PaymentProvider.php

@@ -109,7 +109,7 @@ class PaymentProvider implements PaymentProviderInterface
     {
         $data = $this->notifyService->transactionSuccess($request['headers'], $request['inBody']);
         Log::debug(__METHOD__ . json_encode($data));
-        $inBody = json_decode($inBody, true);
+        $inBody = json_decode($request['inBody'], true);
         if ($inBody['event_type'] == 'TRANSACTION.SUCCESS') {
             // 交易成功
             $payment = $this->extensionPaymentEntity->where([