refactor: use env var for Request Node URL. Fall back to localhost

Author: MantisClone

src/createManyConcurrentRequests.js

@@ -61,7 +61,7 @@
 
     const requestClient = new RequestNetwork({
       nodeConnectionConfig: {
-        baseURL: "http://localhost:3000/",
+        baseURL: process.env.REQUEST_NODE_URL || "http://localhost:3000/",
       },
       signatureProvider: epkSignatureProvider,
     });