Fix fetch in node v20.6.0 (nodejs#2251)

Author: mcollina

lib/core/util.js

@@ -355,15 +355,20 @@ function getSocketInfo (socket) {
   }
 }
 
+async function * convertIterableToBuffer (iterable) {
+  for await (const chunk of iterable) {
+    yield Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk)
+  }
+}
+
 let ReadableStream
 function ReadableStreamFrom (iterable) {
   if (!ReadableStream) {
     ReadableStream = require('stream/web').ReadableStream
   }
 
   if (ReadableStream.from) {
-    // https://github.com/whatwg/streams/pull/1083
-    return ReadableStream.from(iterable)
+    return ReadableStream.from(convertIterableToBuffer(iterable))
   }
 
   let iterator