http2: do not falsely emit 'aborted' on push

A push stream should have its writable side closed upon receipt,
to avoid emitting the 'aborted' event when the readable side
is closed.

Backport-PR-URL: #22850
PR-URL: #22878
Fixes: #22851
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

lib/internal/http2/core.js

@@ -220,6 +220,7 @@ function onSessionHeaders(handle, id, cat, flags, headers) {
       }
     } else {
       stream = new ClientHttp2Stream(session, handle, id, opts);
+      stream.end();
     }
     if (endOfStream)
       stream[kState].endAfterHeaders = true;

test/parallel/test-http2-server-push-stream.js

@@ -54,6 +54,7 @@ server.listen(0, common.mustCall(() => {
       assert.strictEqual(headers['content-type'], 'text/html');
       assert.strictEqual(headers['x-push-data'], 'pushed by server');
     }));
+    stream.on('aborted', common.mustNotCall());
   }));
 
   let data = '';