Remove deprecated calls to `SelectManager#wheres` with no replacement

lib/arel/select_manager.rb

@@ -161,11 +161,6 @@ def orders
       @ast.orders
     end
 
-    def wheres
-      warn "#{caller[0]}: SelectManager#wheres is deprecated and will be removed in Arel 4.0.0 with no replacement"
-      Compatibility::Wheres.new @engine.connection, @ctx.wheres
-    end
-
     def where_sql
       return if @ctx.wheres.empty?
 

test/test_activerecord_compat.rb

-require 'helper'
-
-module Arel
-  describe 'activerecord compatibility' do
-    describe 'select manager' do
-      it 'provides wheres' do
-        table   = Table.new :users
-        manager = Arel::SelectManager.new Table.engine
-        manager.where table[:id].eq 1
-        manager.where table[:name].eq 'Aaron'
-
-        manager.wheres.map { |x|
-          x.value
-        }.join(', ').must_equal "\"users\".\"id\" = 1, \"users\".\"name\" = 'Aaron'"
-      end
-    end
-  end
-end