[Enhancement] Upgrade etcd version in backup-restore

[unmarshall]

Enhancement (What you would like to be added):
Upgrade etcd to 3.4.26, currently 3.4.13 is being used.

Motivation (Why is this needed?):
There was a live canary issue#4122 which points to an upstream issue etcd-io/etcd#7011 which is then fixed in etcd-io/bbolt#225 which is part of bbolt 1.3.7. This version of bbolt is included in 3.4.26 version of etcd. Since this is also the version that is used in etcd-wrapper we should also update backup-restore to use this version (which it is used to start an embedded etcd during restoration).

NOTE: The current version of etcd being vendored is 3.4.13 which uses bbolt version 1.3.3