Fix undefined Rails version for other repos sub-builds

https://github.com/rspec/rspec-support/runs/4956870915?check_suite_focus=true

Author: pirj

Gemfile-rails-dependencies

@@ -32,7 +32,7 @@ end
 # automatically included.  This issue was fixed on the Rails
 # side in Rails 7.0.1, but is not yet fixed in the Rails 6.1.x
 # branch.  Discussion can be found here - https://github.com/mikel/mail/pull/1439
-if RUBY_VERSION >= '3.1' && version.split(' ').last < '7.0'
+if RUBY_VERSION >= '3.1'
   gem 'net-smtp', require: false
   gem 'net-imap', require: false
   gem 'net-pop', require: false