Resolve merge conflicts with hotfix and drop multi_json dependency

Author: numbata

grape-entity.gemspec

@@ -25,7 +25,6 @@ Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
 
   s.add_dependency 'activesupport', '>= 3.0.0'
-  s.add_dependency 'multi_json', '>= 1.0'
 
   s.files         = Dir['lib/**/*.rb', 'CHANGELOG.md', 'LICENSE', 'README.md']
   s.require_paths = ['lib']

lib/grape_entity/entity.rb

@@ -592,13 +592,7 @@ def is_defined_in_entity?(attribute)
 
     def to_json(options = {})
       options = options.to_h if options&.respond_to?(:to_h)
-<<<<<<< HEAD
-      MultiJson.dump(serializable_hash(options))
-||||||| parent of 374a021 (Fix Time serialization regression introduced by dropping MultiJson)
-      Grape::Entity::Json.dump(serializable_hash(options))
-=======
       serializable_hash(options).to_json
->>>>>>> 374a021 (Fix Time serialization regression introduced by dropping MultiJson)
     end
 
     def to_xml(options = {})