tests: factor out base nginx-proxy config

test/test_http3/test_http3-global-disabled.yml

@@ -1,4 +1,8 @@
 services:
+#  nginx-proxy:
+#    environment:
+#      ENABLE_HTTP3: "false"    #Disabled by default
+
   http3-global-disabled:
     image: web
     expose:
@@ -6,10 +10,3 @@ services:
     environment:
       WEB_PORTS: "80"
       VIRTUAL_HOST: http3-global-disabled.nginx-proxy.tld
-
-  sut:
-    image: nginxproxy/nginx-proxy:test
-    volumes:
-      - /var/run/docker.sock:/tmp/docker.sock:ro
-    #environment:
-    #ENABLE_HTTP3: "false"    #Disabled by default