test: make http2 close-while-writing single-shot

The test only needs one request data chunk to queue the server write
and destroy the client stream. Using a persistent data listener can
queue multiple writes and multiple destroys from the same request body,
which makes the test occasionally hang until the harness timeout.

Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com>
Assisted-by: openai:gpt-5.5

Author: trivikr

test/parallel/test-http2-close-while-writing.js

@@ -24,7 +24,7 @@ let client_stream;
 server.on('session', common.mustCall(function(session) {
   session.on('stream', common.mustCall(function(stream) {
     stream.resume();
-    stream.on('data', function() {
+    stream.once('data', function() {
       this.write(Buffer.alloc(1));
       process.nextTick(() => client_stream.destroy());
     });