fix(fetch): fix memory leak when passing keepAlive

.changeset/giant-taxis-breathe.md

@@ -0,0 +1,5 @@
+---
+"@web-std/fetch": patch
+---
+
+Memory leak caused by unregistered listeners. Solution was copied from a node-fetch pr.

packages/fetch/src/fetch.js

@@ -346,13 +346,8 @@ function fixResponseChunkedTransferBadEnding(request, errorCallback) {
 			}
 		};
 
-		socket.prependListener('close', onSocketClose);
-
-		request.on('abort', () => {
-			socket.removeListener('close', onSocketClose);
-		});
-
-		socket.on('data', buf => {
+		/** @param {Buffer} buf */
+		const onData = buf => {
 			properLastChunkReceived = Buffer.compare(buf.slice(-5), LAST_CHUNK) === 0;
 
 			// Sometimes final 0-length chunk and end of message code are in separate packets
@@ -364,7 +359,18 @@ function fixResponseChunkedTransferBadEnding(request, errorCallback) {
 			}
 
 			previousChunk = buf;
-		});
+		};
+
+		socket.prependListener('close', onSocketClose);
+		socket.on('data', onData);
+
+		const removeSocketListeners = () => {
+			socket.removeListener('close', onSocketClose);
+			socket.removeListener('data', onData);
+		}
+
+		request.on('close', removeSocketListeners);
+		request.on('abort', removeSocketListeners);
 	});
 }