Set Gerrit version to 3.11.0-rc3 and JDK 21

Change-Id: I47c2b327053191d7bb445832d7a69114690600cd
diff --git a/common.env b/common.env
index 905886f..9472755 100644
--- a/common.env
+++ b/common.env
@@ -4,8 +4,8 @@
 CLUSTER_KEYS=$(AWS_PREFIX)-cluster-keys
 
 # Gerrit version
-GERRIT_VERSION=3.8
-GERRIT_PATCH=2
+GERRIT_VERSION=3.11
+GERRIT_PATCH=0-rc3
 GERRIT_BRANCH=stable-$(GERRIT_VERSION)
 
 # Gerrit CI