http2: do not crash on stream listener removal w/ destroyed session

Do not crash when the session is no longer available.

Fixes: https://github.com/nodejs/node/issues/29457

PR-URL: https://github.com/nodejs/node/pull/29459
Backport-PR-URL: https://github.com/nodejs/node/pull/29618


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>