Currently, metacpan-api has an app.psgi for the Catalyst app. This has
most of the end points. There is also an api.pl script which runs
Mojolicious. This hosts a Minion admin interface, a few end points which
are duplicates of the Catalyst end points, and mounts the app.psgi to
handle everything else.

This setup uses the Mojolicious MountPSGI plugin. This plugin is rather
limited and has some issues. It ends up loading the PSGI app the first
time it is requested. This means in a prefork setup, none of the memory
is shared. This is wasteful, but also means creating worker processes is
very slow. And if it is slow enough, the worker won't respond to the
heartbeat check, and the parent process will kill it before it is even
ready.

The problems with MountPSGI could be fixed, but the Mojolicious app is
also just adding complexity without providing any real value in its
current state. The end points it provides are duplicates.

We aren't using the Minion integration to dispatch tasks anywhere in the
API. And its admin interface doesn't really belong in the same service
as the API server.

Simplify the way metacpan-api is hosted by just running the Catalyst
app. This avoids the problems with the MountPSGI plugin. Replacing the
Minion admin interface is a task left for a different time.

Using Mojolicous in the future would be reasonable, but it should be
done as a proper conversion.