Raise exceptions on invalid cache expiration time

It doesn't really affect us (unless some of our dependencies make this
mistake) because we only use `expires_in/expires_at` once and we do it
correctly, but it might be help us detect this issue if we ever
introduce it in the future.

config/initializers/new_framework_defaults_7_1.rb

@@ -91,7 +91,7 @@ Rails.application.config.active_job.use_big_decimal_serializer = true
 # Options are `true`, and `false`. If `false`, the exception will be reported
 # as `handled` and logged instead.
 #++
-# Rails.application.config.active_support.raise_on_invalid_cache_expiration_time = true
+Rails.application.config.active_support.raise_on_invalid_cache_expiration_time = true
 
 ###
 # Specify whether Query Logs will format tags using the SQLCommenter format