copr-be: Increase the worker allocation to 90 per owner

This still doesn't mean that one project (= sandbox) can waste that
many workers, we still keep the per/sandbox limit on 35.  This change
though drastically helps Packit which serves many users under a single
owner (but multiple sandboxes).

roles/copr/backend/templates/copr-be.conf.j2

@@ -56,7 +56,7 @@ builds_max_workers_arch=
 
 # Maximum number of concurrently running tasks per project owner.
 {% if env == 'production' %}
-builds_max_workers_owner=45
+builds_max_workers_owner=90
 {% elif devel %}
 builds_max_workers_owner=15
 {% else %}