Patch `grape-entity` to prevent having NameError loop

RubyVM starts raising unlimited amount of `NameError` errors in case of
a `NameError` in our Grape::Entity instances because of a bug exists in
the `grape-entity` gem.

This causes high CPU usage and puts us at the risk of having DoS.
The VM would eventually raise a `SystemStackError` but this takes quite
long time because the repeating frames are huge.

You can track the progress of upstream fix here:
https://github.com/ruby-grape/grape-entity/pull/355

Changelog: fixed

config/initializers_before_autoloader/grape_entity_patch.rb

+# frozen_string_literal: true
+
+# This can be removed after the problem gets fixed on upstream.
+# You can follow https://github.com/ruby-grape/grape-entity/pull/355 to see the progress.
+#
+# For more information about the issue;
+# https://github.com/ruby/did_you_mean/issues/158#issuecomment-906056018
+
+require 'grape-entity'
+
+module Grape
+  class Entity
+    # Upstream version: https://github.com/ruby-grape/grape-entity/blob/675d3c0e20dfc1d6cf6f5ba5b46741bd404c8be7/lib/grape_entity/entity.rb#L520
+    def exec_with_object(options, &block)
+      if block.parameters.count == 1
+        instance_exec(object, &block)
+      else
+        instance_exec(object, options, &block)
+      end
+    rescue StandardError => e
+      # it handles: https://github.com/ruby/ruby/blob/v3_0_0_preview1/NEWS.md#language-changes point 3, Proc
+      raise Grape::Entity::Deprecated.new e.message, 'in ruby 3.0' if e.is_a?(ArgumentError)
+
+      raise e
+    end
+  end
+end

spec/config/grape_entity_patch_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Grape::Entity patch' do
+  let(:entity_class) { Class.new(Grape::Entity) }
+
+  describe 'NameError in block exposure with argument' do
+    subject(:represent) { entity_class.represent({}, serializable: true) }
+
+    before do
+      entity_class.expose :raise_no_method_error do |_|
+        foo
+      end
+    end
+
+    it 'propagates the error to the caller' do
+      expect { represent }.to raise_error(NameError)
+    end
+  end
+end