Update etcd to 3.6.8

Author: Schmaetz

Makefile

@@ -11,7 +11,7 @@ OLD_PG_VERSIONS ?= 13 14 15 16 17
 PATRONI_VERSION ?= multisite-4.1.0.0
 PGBACKREST_VERSION ?= 2.58.0
 POSTGIS_VERSION ?= 36
-ETCD_VERSION ?= 3.6.7
+ETCD_VERSION ?= 3.6.8
 PGBOUNCER_VERSION ?= 1.25
 PACKAGER ?= dnf
 BUILD ?= 1