Update etcd version to 3.4.27

* etcd 3.3 is no longer maintained.
* etcd 3.4 removes deprecated interfaces, and clients may
  need updated configs.
* The cinder backend coordination URL needs to explicitly
  specify the version, until tooz can be updated
  https://review.opendev.org/c/openstack/tooz/+/891355
* etcd only supports in-place upgrades between minor
  versions, so any jobs testing upgrades could fail if
  they skip from 3.2 directly to 3.4

Change-Id: Ifcecdffa17a3a2b1075aa503978c44545c4a2a3c
diff --git a/stackrc b/stackrc
index 0d1880c..2d25e37 100644
--- a/stackrc
+++ b/stackrc
@@ -728,11 +728,11 @@
 EXTRA_CACHE_URLS=""
 
 # etcd3 defaults
-ETCD_VERSION=${ETCD_VERSION:-v3.3.12}
-ETCD_SHA256_AMD64=${ETCD_SHA256_AMD64:-"dc5d82df095dae0a2970e4d870b6929590689dd707ae3d33e7b86da0f7f211b6"}
-ETCD_SHA256_ARM64=${ETCD_SHA256_ARM64:-"170b848ac1a071fe7d495d404a868a2c0090750b2944f8a260ef1c6125b2b4f4"}
-ETCD_SHA256_PPC64=${ETCD_SHA256_PPC64:-"77f807b1b51abbf51e020bb05bdb8ce088cb58260fcd22749ea32eee710463d3"}
-# etcd v3.2.x doesn't have anything for s390x
+ETCD_VERSION=${ETCD_VERSION:-v3.4.27}
+ETCD_SHA256_AMD64=${ETCD_SHA256_AMD64:-"a32d21e006252dbc3405b0645ba8468021ed41376974b573285927bf39b39eb9"}
+ETCD_SHA256_ARM64=${ETCD_SHA256_ARM64:-"ed7e257c225b9b9545fac22246b97f4074a4b5109676e92dbaebfb9315b69cc0"}
+ETCD_SHA256_PPC64=${ETCD_SHA256_PPC64:-"eb8825e0bc2cbaf9e55947f5ee373ebc9ca43b6a2ea5ced3b992c81855fff37e"}
+# etcd v3.2.x and later doesn't have anything for s390x
 ETCD_SHA256_S390X=${ETCD_SHA256_S390X:-""}
 # Make sure etcd3 downloads the correct architecture
 if is_arch "x86_64"; then