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.

PR-URL: https://github.com/nodejs/node/pull/22878
Fixes: https://github.com/nodejs/node/issues/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>