Fix compatibility with rails-head when duplicated advisory lockable column

[Earlopain]

The primary key and column may be identical. Current rails head will select this column twice, which confuses postgres.

Draft for now, let's first see how rails/rails#53747 goes.

[Earlopain]

Seems this expectation was wrong from the start. I don't think this would execute, same as in the issue

[bensheldon]

This looks like a great fix! Simple and definitely better now 🙇🏻

[bensheldon]

I think we may as well fix this in GoodJob. I'd like to make one tweak to see if I can avoid the array/uniq calculation because I think it would be marginally more efficient to do an == check`. I can land this 🫡

[Earlopain]

Yeah, sure. You may also want to drop the to_sym conversion. I think there was one test that stubbed a symbol in but generally I think tests would catch if you pass advisory_lockable_column a symbol wich is the same as the primary key.

[bensheldon]

You may also want to drop the to_sym conversion.

I eventually plan to extract advisory_lockable.rb to a separate gem (I'm already using it in a few projects) so I want to be defensive about its inputs. I also wish Active Record was clear about when it wants symbols and when it wants strings; I frequently see a symbol input documented but when I go read the code it's coercing it to a string internally 🤷🏻