chore: robots.txt should be handled by frontend services, not API

.env

@@ -50,7 +50,7 @@ HTTP_CACHE_STALE_WHILE_REVALIDATE=60
 # Default dev env use varnish
 HOSTNAME_VARNISH=`roadiz-skeleton.test`,`roadiz-skeleton.local`
 # Use traefik path_prefix to host API and NuxtJS on the same domain
-PATH_PREFIX=`/rz-admin`,`/files`,`/assets`,`/themes`,`/bundles`,`/robots.txt`,`/api`,`/_wdt`,`/_profiler`,`/css/main-color.css`,`/custom-form`,`/css/login/image`
+PATH_PREFIX=`/rz-admin`,`/files`,`/assets`,`/themes`,`/bundles`,`/api`,`/_wdt`,`/_profiler`,`/css/main-color.css`,`/custom-form`,`/css/login/image`
 
 REDIRECT_REGEX=^(https?)://api\.roadiz\-skeleton\.test/(.*)
 ## Dollar char may be interpolated or not depending your system