Allow attr_encrypted version four

As of version 4.0.0, attr_encrypted supports Rails 7.

This change relaxes the version requirement for attr_encrypted so that
there's a path to upgrade to Rails 7 while staying in the
`devise-two-factor` 4.x series, for apps who are ready for the Rails
update but not yet ready for the `devise-two-factor` 5.x update.

Relevant attr_encrypted version: attr-encrypted/attr_encrypted@b565876
Rails 7 changes: attr-encrypted/attr_encrypted#434

devise-two-factor.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
 
   s.add_runtime_dependency 'railties',       '< 7.1'
   s.add_runtime_dependency 'activesupport',  '< 7.1'
-  s.add_runtime_dependency 'attr_encrypted', '>= 1.3', '< 4', '!= 2'
+  s.add_runtime_dependency 'attr_encrypted', '>= 1.3', '< 5', '!= 2'
   s.add_runtime_dependency 'devise',         '~> 4.0'
   s.add_runtime_dependency 'rotp',           '~> 6.0'
 

spec/devise/models/two_factor_authenticatable_spec.rb

@@ -64,15 +64,15 @@ def save(validate)
 
     describe 'otp_secret options' do
       it 'should be of the key' do
-        expect(subject.encrypted_attributes[:otp_secret][:key]).to eq('test-key'*8)
+        expect(subject.attr_encrypted_encrypted_attributes[:otp_secret][:key]).to eq('test-key'*8)
       end
 
       it 'should be of the mode' do
-        expect(subject.encrypted_attributes[:otp_secret][:mode]).to eq(:per_attribute_iv_and_salt)
+        expect(subject.attr_encrypted_encrypted_attributes[:otp_secret][:mode]).to eq(:per_attribute_iv_and_salt)
       end
 
       it 'should be of the mode' do
-        expect(subject.encrypted_attributes[:otp_secret][:algorithm]).to eq('aes-256-cbc')
+        expect(subject.attr_encrypted_encrypted_attributes[:otp_secret][:algorithm]).to eq('aes-256-cbc')
       end
     end
   end