nginx server_name regex before exact match

I want to implement a LetsEncrypt acme-challenge location statement globally for any server_name which ever will be requested.

So I wrote the following server block :

server {
        server_name ~^(.+)$;
        listen 80;

        location ^~ /.well-known/acme-challenge/ {
                default_type "text/plain";
                root        /etc/nginx/ssl/le;
                allow all;
        }
}

From what I think I know, I understand that if there is an exact match of a server-block, my server-block above will not be invoked.

Is there any trick how to accomplish it without ever touching the actual server-blocks of the domains?

I'm even fine with an if-statement