bump up server's maturity

VERSION

 MYSQL_VERSION_MAJOR=10
 MYSQL_VERSION_MINOR=7
 MYSQL_VERSION_PATCH=2
-SERVER_MATURITY=gamma
+SERVER_MATURITY=stable

mysql-test/suite/sys_vars/r/sysvars_star.result

@@ -60,7 +60,7 @@ VARIABLE_NAME	PLUGIN_MATURITY
 SESSION_VALUE	NULL
 GLOBAL_VALUE	alpha
 GLOBAL_VALUE_ORIGIN	CONFIG
-DEFAULT_VALUE	beta
+DEFAULT_VALUE	gamma
 VARIABLE_SCOPE	GLOBAL
 VARIABLE_TYPE	ENUM
 VARIABLE_COMMENT	The lowest desirable plugin maturity. Plugins less mature than that will not be installed or loaded

plugin/type_uuid/mysql-test/type_uuid/type_uuid_plugin.result

@@ -24,7 +24,7 @@ PLUGIN_TYPE	DATA TYPE
 PLUGIN_AUTHOR	MariaDB Corporation
 PLUGIN_DESCRIPTION	Data type UUID
 PLUGIN_LICENSE	GPL
-PLUGIN_MATURITY	Beta
+PLUGIN_MATURITY	Gamma
 PLUGIN_AUTH_VERSION	1.0
 #
 # End of 10.5 tests