Fixes #20518 - set pulp tasks to 2

[chris1984]

Downstream this change was made for performance reasons, reference in the following BZ:

https://bugzilla.redhat.com/show_bug.cgi?id=1388631

[ekohl]

Where does the number 2 come from? Setting this 2 also means the text (from the bugzilla) "To disable this completely, users can set '--katello-max-tasks-per-pulp-worker' to 'undef'." needs to be changed to to '0'.

[chris1984]

@ekohl it comes from https://bugzilla.redhat.com/show_bug.cgi?id=1388631#c19 I can let @beav comment more on this why the change was made as he was doing the perf stuff. in 6.2 its set to 2 and needs to be set to 2 for 6.3/upstream.

[beav]

There is nothing special about the number 2, I think the pulp team settled on it after testing and noticing that it's extremely cheap to shut down and spin up a new worker process, so it's done after every other task. You could probably pick another small number and it would work similarly but 2 is the convention. I've never seen issues with 2, but I would most likely say the same if it was any other reasonably small number 😸