Update env-example

Added missing symfony install variable and added new python install variable

env-example

@@ -45,6 +45,8 @@ WORKSPACE_INSTALL_LARAVEL_INSTALLER=false
 WORKSPACE_INSTALL_DEPLOYER=false
 WORKSPACE_INSTALL_LINUXBREW=false
 WORKSPACE_INSTALL_MC=false
+WORKSPACE_INSTALL_SYMFONY=false
+WORKSPACE_INSTALL_PYTHON=false
 WORKSPACE_INSTALL_IMAGE_OPTIMIZERS=false
 WORKSPACE_PUID=1000
 WORKSPACE_PGID=1000