Publish monthly lists on last day of month instead of 28th

[rfromthecastle]

User stories

As a Registry Maintainer, I would like to be able to publish monthly versions of lists at the last day of the month rather than the 28th

Problems this relates to

Data management

Proposed solution

Set monthly lists to be published on the last day of the month

Considered alternatives

None

Additional context

None

[rfromthecastle]

I know the list series frequency functionality works based on a day number + frequency, but I think there should be an option for last day of the month, as this differs depending on the month.