Rails 7 default_timezone is a module instance variable

[yahonda]

This commit addresses the following failure.

$ bundle exec rspec ./spec/ransack/adapters/active_record/base_spec.rb:316
Run options: include {:locations=>{"./spec/ransack/adapters/active_record/base_spec.rb"=>[316]}}
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Running Ransack specs with SQLite, Active Record 7.0.0.alpha, Arel 10.0.0 and Ruby 3.0.1
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F

Failures:

  1) Ransack::Adapters::ActiveRecord::Base#ransacker should function correctly with a multi-parameter attribute
     Failure/Error: ::ActiveRecord::Base.default_timezone = :utc

     NoMethodError:
       undefined method `default_timezone=' for ActiveRecord::Base:Class
       Did you mean?  default_timezone
     # /home/yahonda/src/github.com/rails/rails/activerecord/lib/active_record/dynamic_matchers.rb:22:in `method_missing'
     # ./spec/ransack/adapters/active_record/base_spec.rb:317:in `block (3 levels) in <module:ActiveRecord>'

Finished in 0.89225 seconds (files took 1.47 seconds to load)
1 example, 1 failure

Failed examples:

rspec ./spec/ransack/adapters/active_record/base_spec.rb:316 # Ransack::Adapters::ActiveRecord::Base#ransacker should function correctly with a multi-parameter attribute

Coverage report generated for RSpec to /home/yahonda/src/github.com/activerecord-hackery/ransack/coverage. 156 / 192 LOC (81.25%) covered.
Stopped processing SimpleCov as a previous error not related to SimpleCov has been detected
$

Fixes #1229
Refer rails/rails@c6e4dbe

[deivid-rodriguez]

Thank you! Even if this was just deprecated in the end, it makes sense to use the blessed way :)