Fix a few method redefinition warnings

[Earlopain]

2 enum values conflict with already existing scopes: "retried" and "discarded" (oops) (#1420)

"running" and "finished" got moved from the discrete execution cleanup (#1427). This change I'm not so certain about which of these two is the correct one. Tests do pass but you'd better check these two anyways, this just removes the earlier definition:

# first
scope :running, -> { where.not(performed_at: nil).where(finished_at: nil).joins_advisory_locks.where.not(pg_locks: { locktype: nil }) }
# second
scope :running, -> { where.not(performed_at: nil).where(finished_at: nil) }

# first
scope :finished, -> { where.not(finished_at: nil) }
# second
scope :finished, ->(timestamp = nil) { timestamp ? where(arel_table['finished_at'].lteq(bind_value('finished_at', timestamp, ActiveRecord::Type::DateTime))) : where.not(finished_at: nil) }

[bensheldon]

Thank you so much for catching these! I must have something wonky in my test setup that I'm not seeing these warnings.

I just chose the other versions 😁 There is already a finished_before method that did the same thing as taking an argument.

[Earlopain]

Looks good, thanks. You just have to set $VERBOSE = true for these to appear (which I tend to do). I would have done this here already but there are two other minor things to get out of the way first.