Merge branch '10.6' of https://github.com/mariadb/server into 10.6

VERSION

 MYSQL_VERSION_MAJOR=10
 MYSQL_VERSION_MINOR=6
-MYSQL_VERSION_PATCH=4
+MYSQL_VERSION_PATCH=5
 SERVER_MATURITY=stable

mysql-test/main/func_group.test

 #
 # simple test of all group functions
 #
+if (`SELECT $PS_PROTOCOL != 0`)
+{
+   --skip Test temporarily disabled for ps-protocol
+}
 
 --disable_warnings
 drop table if exists t1,t2,t3,t4,t5,t6;