increase INET6 plugin maturity

plugin/type_inet/mysql-test/type_inet/type_inet6_plugin.result

@@ -24,7 +24,7 @@ PLUGIN_TYPE	DATA TYPE
 PLUGIN_AUTHOR	MariaDB Corporation
 PLUGIN_DESCRIPTION	Data type INET6
 PLUGIN_LICENSE	GPL
-PLUGIN_MATURITY	Beta
+PLUGIN_MATURITY	Gamma
 PLUGIN_AUTH_VERSION	1.0
 #
 # End of 10.5 tests

plugin/type_inet/plugin.cc

@@ -186,7 +186,7 @@ maria_declare_plugin(type_inet)
   NULL,                         // Status variables
   NULL,                         // System variables
   "1.0",                        // String version representation
-  MariaDB_PLUGIN_MATURITY_BETA  // Maturity(see include/mysql/plugin.h)*/
+  MariaDB_PLUGIN_MATURITY_GAMMA // Maturity(see include/mysql/plugin.h)*/
 },
 {
   MariaDB_FUNCTION_PLUGIN,      // the plugin type (see include/mysql/plugin.h)