Remove unused variable (matrix_nginx_proxy_synapse_workers_enabled_list) definition

roles/matrix-nginx-proxy/defaults/main.yml

@@ -218,7 +218,6 @@ matrix_nginx_proxy_proxy_matrix_identity_api_addr_sans_container: "127.0.0.1:{{
 
 # Controls whether proxying for metrics (`/_synapse/metrics`) should be done (on the matrix domain)
 matrix_nginx_proxy_proxy_synapse_metrics: false
-matrix_nginx_proxy_synapse_workers_enabled_list: []
 matrix_nginx_proxy_proxy_synapse_metrics_basic_auth_enabled: false
 # The following value will be written verbatim to the htpasswd file that stores the password for nginx to check against and needs to be encoded appropriately.
 # Read the manpage at `man 1 htpasswd` to learn more, then encrypt your password, and paste the encrypted value here.