Remove bootsnap dependency

[pierre]

For Kaui to run on jdk17 (killbill/killbill-cloud#280), I had to remove bootsnap from Gemfile.lock. I'm not quite sure if it's related to Shopify/bootsnap#162, but the exact same war runs on jdk11 but doesn't start on jdk17. 🤷

Let's remove the dependency.

• Is removing it from

  killbill-admin-ui/kaui.gemspec

  Line 26 in 1427939

  s.add_dependency 'bootsnap'

  enough?
• Otherwise, https://jeremy.wadsack.com/2018/10/05/disable-rails-bootsnap-in-production/ might help?

For testing, ensure bootsnap isn't present in the final killbill-admin-ui-standalone Gemfile.lock.