[Misc] Remove no more supported version 11.x

11/mysql-tomcat/.env

11/mysql-tomcat/Dockerfile

11/mysql-tomcat/docker-compose.yml

11/mysql-tomcat/mysql/init.sql

11/mysql-tomcat/mysql/xwiki.cnf

11/mysql-tomcat/tomcat/setenv.sh

11/mysql-tomcat/xwiki/docker-entrypoint.sh

11/mysql-tomcat/xwiki/hibernate.cfg.xml

11/postgres-tomcat/.env

11/postgres-tomcat/Dockerfile

11/postgres-tomcat/docker-compose.yml

11/postgres-tomcat/tomcat/setenv.sh

11/postgres-tomcat/xwiki/docker-entrypoint.sh

11/postgres-tomcat/xwiki/hibernate.cfg.xml

build.gradle