Remove reimbursement methods from StoreCreditCategory

It removes:

- .reimbursement_category_name
- .reimbursement_category_name=
- .reimbursement_category
- #reimbursement_category_name

ref: solidusio#3507

core/app/models/spree/store_credit_category.rb

@@ -7,39 +7,7 @@ class Spree::StoreCreditCategory < Spree::Base
   class_attribute :non_expiring_credit_types
   self.non_expiring_credit_types = [Spree::StoreCreditType::NON_EXPIRING]
 
-  # @deprecated
-  class_attribute :reimbursement_category_name
-  self.reimbursement_category_name = I18n.t('spree.store_credit_category.default')
-
-  # @deprecated
-  def self.reimbursement_category(reimbursement)
-    reimbursement.store_credit_category
-  end
-
   def non_expiring?
     self.class.non_expiring_credit_types.include? name
   end
-
-  public_instance_methods.grep(/^reimbursement_category_name/).each do |method|
-    deprecate(
-      method => 'Use Spree::Reimbursement#store_credit_category.name instead',
-      deprecator: Spree::Deprecation
-    )
-  end
-
-  class << self
-    public_instance_methods.grep(/^reimbursement_category_name/).each do |method|
-      deprecate(
-        method => 'Use Spree::Reimbursement.store_credit_category.name instead',
-        deprecator: Spree::Deprecation
-      )
-    end
-
-    public_instance_methods.grep(/^reimbursement_category$/).each do |method|
-      deprecate(
-        method => 'Use Spree::Reimbursement.store_credit_category instead',
-        deprecator: Spree::Deprecation
-      )
-    end
-  end
 end

core/spec/models/spree/store_credit_category_spec.rb

@@ -16,26 +16,4 @@
       it { expect(store_credit_category).not_to be_non_expiring }
     end
   end
-
-  describe '.reimbursement_category' do
-    it 'raises a dreprecation warning' do
-      allow(Spree::Deprecation).to receive(:warn)
-
-      described_class.reimbursement_category(Spree::Reimbursement.new)
-
-      expect(Spree::Deprecation).to have_received(:warn)
-        .with(/reimbursement_category /, any_args)
-    end
-  end
-
-  describe '.reimbursement_category_name' do
-    it 'raises a dreprecation warning' do
-      allow(Spree::Deprecation).to receive(:warn)
-
-      described_class.reimbursement_category_name
-
-      expect(Spree::Deprecation).to have_received(:warn)
-        .with(/reimbursement_category_name /, any_args)
-    end
-  end
 end