Upgrade rack to 2.1.4
Upgrade rack to 2.1.4

Because of https://github.com/advisories/GHSA-j6w9-fv6q-3q52

RailsEventStore/rails_event_store,mpraglowski/rails_event_store,mpraglowski/rails_event_store,RailsEventStore/rails_event_store,arkency/rails_event_store,mpraglowski/rails_event_store,arkency/rails_event_store,arkency/rails_event_store,arkency/rails_event_store,RailsEventStore/rails_event_store,mpraglowski/rails_event_store,RailsEventStore/rails_event_store