Add ruby 3.4 to the test matrix

[jcoyne]

No description provided.

[seanaery]

Thanks @jcoyne . Looks like the failing tests here are because ruby dropped the csv gem from the standard library in 3.4.0. So I think we probably just need to explicitly require it in the arclight gemspec now, i.e., spec.add_dependency 'csv'

[jcoyne]

@seanaery we don't use the CSV gem in Arclight though, so it seems wrong to fix it here. I think sul-dlss/traject_plus#39 is what we're waiting for.

[seanaery]

@jcoyne Aha, you're right -- thanks for the heads-up about traject_plus.