etcd: bump etcd sdk to v3.6.10

Bump go.etcd.io/etcd/{api,client/pkg,client,pkg,server}/v3 from v3.6.8 to v3.6.10.
go.etcd.io/etcd/raft/v3 is intentionally left unchanged (separate release cadence).

Signed-off-by: Humble Devassy Chirammal <humble.devassy@gmail.com>

Kubernetes-commit: 15492a41ed637237cf1891ef140544f64197643d