DEV: Upgrade Rails to version 7.1 (#27539)

* DEV: Upgrade Rails to 7.1

* FIX: Remove references to `Rails.logger.chained`

`Rails.logger.chained` was provided by Logster before Rails 7.1
introduced their broadcast logger. Now all the loggers are added to
`Rails.logger.broadcasts`.

Some code in our initializers was still using `chained` instead of
`broadcasts`.

* DEV: Make parameters optional to all FakeLogger methods

* FIX: Set `override_level` on Logster loggers (#27519)

A followup to f595d599dd361b7fb39fb3c82cbc11d19d518c19

* FIX: Don’t duplicate Rack response

---------

Co-authored-by: Jarek Radosz <jradosz@gmail.com>

lib/discourse.rb

@@ -954,14 +954,7 @@ module Discourse
   def self.warn(message, env = nil)
     append = env ? (+" ") << env.map { |k, v| "#{k}: #{v}" }.join(" ") : ""
 
-    if !(Logster::Logger === Rails.logger)
-      Rails.logger.warn("#{message}#{append}")
-      return
-    end
-
-    loggers = [Rails.logger]
-    loggers.concat(Rails.logger.chained) if Rails.logger.chained
-
+    loggers = Rails.logger.broadcasts
     logster_env = env
 
     if old_env = Thread.current[Logster::Logger::LOGSTER_ENV]
@@ -1116,16 +1109,7 @@ module Discourse
       end
     end
 
-    schema_cache = ActiveRecord::Base.connection.schema_cache
-
     RailsMultisite::ConnectionManagement.safe_each_connection do
-      # load up schema cache for all multisite assuming all dbs have
-      # an identical schema
-      dup_cache = schema_cache.dup
-      # this line is not really needed, but just in case the
-      # underlying implementation changes lets give it a shot
-      dup_cache.connection = nil
-      ActiveRecord::Base.connection.schema_cache = dup_cache
       I18n.t(:posts)
 
       # this will force Cppjieba to preload if any site has it