Localize patch for AR::Relation#primary_key in Rails 8.0+

[kymmt90]

Rework of #238.

Problem

Only AR::Relation's primary_key is overridden with bitemporal_id_key globally.

activerecord-bitemporal/lib/activerecord-bitemporal/bitemporal.rb

Lines 171 to 173 in 35410b4

	def primary_key
	bitemporal_id_key
	end

Therefore, when model.primary_key is called in Rails 8.0+'s finder methods, it returns the original primary_key value instead of bitemporal_id_key. Additionally, this override can cause various other confusions.

Changes

This PR removes the global override of AR::Relation#primary_key in Rails 8.0+. The order of AR objects fetched by finder methods is kept as before thanks to #237.

By removing the global override of primary_key, AR::Calculations#ids/#exists? now uses swapped_id instead of bitemporal_id. This is because those methods calls primary_key on self.

• #ids: https://github.com/rails/rails/blob/v8.0.4/activerecord/lib/active_record/relation/calculations.rb#L371
• #exists?: https://github.com/rails/rails/blob/v8.0.4/activerecord/lib/active_record/relation/finder_methods.rb#L452

This PR redefines #ids and #exists? to override primary_key locally as #find does.

[krororo]

LGTM 👍

[krororo]

I've confirmed the changes. It looks good to me.

[osyo-manga]

Thanks :)