Fix ActiveSupport loading.

Cherry-picked from df9cdae:

RUBY-2834 support rails 7.0 (#2399)

* RUBY-2834 support rails 7.0

* fix as require

Co-authored-by: Oleg Pudeyev <[email protected]>

Author: p-mongo

spec/lite_spec_helper.rb

@@ -157,6 +157,13 @@ class ExampleTimeout < StandardError; end
 end
 
 if SpecConfig.instance.active_support?
+  require "active_support/version"
+  if ActiveSupport.version >= Gem::Version.new(7)
+    # ActiveSupport wants us to require ALL of it all of the time.
+    # See: https://github.com/rails/rails/issues/43851,
+    # https://github.com/rails/rails/issues/43889, etc.
+    require 'active_support'
+  end
   require "active_support/time"
   require 'mongo/active_support'
 end