Bump etcd version to 3.4.9 to pick up a few bug fixes, notably:

• Fix inconsistency between WAL and server snapshot. (Fix state.commit is out of range on restart etcd-io/etcd#11888)
• Fix a data corruption bug when etcd auth is enabled. (auth/store: save consistentIndex to fix a data corruption bug etcd-io/etcd#11652)

Todo:

• Update etcd client version (Update etcd client to v3.4.9 #92075)
• Update etcd server version in Makefile under cluster/images/etcd (Update etcd makefile to build 3.4.9 image #92078)
• Test and promote images from staging to prod repo (Promote etcd 3.4.9-0 k8s.io#973)
• Update default etcd server version everywhere in codebase (Update default etcd server to 3.4.9 #92349)

/sig api-machinery
/kind feature