Remove Ruby 2.4 from the CI matrix
Remove Ruby 2.4 from the CI matrix

Rails 6 requires Ruby 2.5+ or newer.
See https://github.com/rails/rails/pull/34754.

betesh/rails,BlakeWilliams/rails,iainbeeston/rails,mechanicles/rails,iainbeeston/rails,yahonda/rails,yalab/rails,betesh/rails,yawboakye/rails,kmcphillips/rails,Erol/rails,fabianoleittes/rails,vipulnsward/rails,prathamesh-sonpatki/rails,arunagw/rails,georgeclaghorn/rails,yhirano55/rails,yhirano55/rails,eileencodes/rails,utilum/rails,lcreid/rails,Edouard-chin/rails,joonyou/rails,esparta/rails,Envek/rails,yahonda/rails,shioyama/rails,EmmaB/rails-1,Envek/rails,betesh/rails,Erol/rails,MSP-Greg/rails,rails/rails,flanger001/rails,mechanicles/rails,utilum/rails,Envek/rails,notapatch/rails,vipulnsward/rails,BlakeWilliams/rails,BlakeWilliams/rails,repinel/rails,Stellenticket/rails,eileencodes/rails,flanger001/rails,bogdanvlviv/rails,Edouard-chin/rails,kddeisz/rails,schuetzm/rails,yahonda/rails,rafaelfranca/omg-rails,shioyama/rails,yalab/rails,starknx/rails,palkan/rails,Vasfed/rails,lcreid/rails,iainbeeston/rails,Stellenticket/rails,Edouard-chin/rails,tjschuck/rails,tgxworld/rails,Erol/rails,tjschuck/rails,bogdanvlviv/rails,arunagw/rails,yahonda/rails,prathamesh-sonpatki/rails,flanger001/rails,rafaelfranca/omg-rails,MSP-Greg/rails,tgxworld/rails,jeremy/rails,prathamesh-sonpatki/rails,Stellenticket/rails,shioyama/rails,Envek/rails,notapatch/rails,yhirano55/rails,mechanicles/rails,yawboakye/rails,esparta/rails,jeremy/rails,gauravtiwari/rails,eileencodes/rails,tgxworld/rails,bogdanvlviv/rails,utilum/rails,schuetzm/rails,mechanicles/rails,EmmaB/rails-1,repinel/rails,esparta/rails,starknx/rails,vipulnsward/rails,palkan/rails,BlakeWilliams/rails,MSP-Greg/rails,fabianoleittes/rails,palkan/rails,gauravtiwari/rails,joonyou/rails,kddeisz/rails,yawboakye/rails,EmmaB/rails-1,yawboakye/rails,notapatch/rails,rails/rails,palkan/rails,georgeclaghorn/rails,yalab/rails,joonyou/rails,flanger001/rails,kmcphillips/rails,Vasfed/rails,Vasfed/rails,georgeclaghorn/rails,tjschuck/rails,esparta/rails,yalab/rails,arunagw/rails,lcreid/rails,MSP-Greg/rails,Stellenticket/rails,bogdanvlviv/rails,fabianoleittes/rails,repinel/rails,Edouard-chin/rails,jeremy/rails,shioyama/rails,arunagw/rails,yhirano55/rails,schuetzm/rails,rafaelfranca/omg-rails,lcreid/rails,fabianoleittes/rails,Erol/rails,eileencodes/rails,kddeisz/rails,rails/rails,tgxworld/rails,vipulnsward/rails,utilum/rails,prathamesh-sonpatki/rails,kddeisz/rails,iainbeeston/rails,georgeclaghorn/rails,gauravtiwari/rails,tjschuck/rails,repinel/rails,joonyou/rails,rails/rails,notapatch/rails,betesh/rails,kmcphillips/rails,starknx/rails,jeremy/rails,schuetzm/rails,Vasfed/rails,kmcphillips/rails