meta: add codeowner for src/node_snapshot*

PR-URL: #44113
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

.github/CODEOWNERS

@@ -109,6 +109,7 @@
 /src/node.cc @nodejs/startup
 /src/node_code_cache_stub.cc @nodejs/startup
 /src/node_native_module* @nodejs/startup
+/src/node_snapshot* @nodejs/startup
 /lib/internal/bootstrap/* @nodejs/startup
 /tools/code_cache/* @nodejs/startup
 /tools/snapshot/* @nodejs/startup