add explicit HTTP agents with keepAlive to bru.sendRequest axios instance

packages/bruno-requests/src/network/axios-instance.ts

@@ -1,4 +1,6 @@
 import { default as axios, AxiosRequestConfig, AxiosRequestHeaders, AxiosResponse, InternalAxiosRequestConfig } from 'axios';
+import http from 'node:http';
+import https from 'node:https';
 
 /**
  * 
@@ -25,6 +27,8 @@ type ModifiedAxiosResponse = AxiosResponse & {
 }
 
 const baseRequestConfig: Partial<AxiosRequestConfig> = {
+  httpAgent: new http.Agent({ keepAlive: true }),
+  httpsAgent: new https.Agent({ keepAlive: true }),
   transformRequest: function transformRequest(data: any, headers: AxiosRequestHeaders) {
     const contentType = headers.getContentType() || '';
     const hasJSONContentType = contentType.includes('json');