bigdecimal no longer part of the default gems warning

[bgsmase]

I have started getting warnings such as below when executing timetrap commands using version 1.15.2:

lib/ruby/gems/3.3.0/gems/sequel-5.30.0/lib/sequel.rb:3: warning: bigdecimal was loaded from the standard library, but will no longer be part of the default gems starting from Ruby 3.4.0. You can add bigdecimal to your Gemfile or gemspec to silence this warning.

I see from looking at the sequel code that this was fixed there in https://github.com/jeremyevans/sequel/commit/c6a017810848d6222b01310d063ce404deddd772 and so should be in versions from 5.72.0 and later of sequel. Timetrap currently depends on version sequel 5.30.0 so can this be updated.