Update rubocop requirement from 1.48 to 1.60.0 (#921)

Updates the requirements on [rubocop](https://github.com/rubocop/rubocop) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop@v1.48.0...v1.60.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.rubocop.yml

@@ -59,3 +59,6 @@ Metrics/ModuleLength:
   Exclude:
     - 'lib/chewy/rake_helper.rb'
     - '**/*_spec.rb'
+
+Style/ArgumentsForwarding:
+  Enabled: false

gemfiles/base.gemfile

@@ -6,7 +6,7 @@ gem 'rake'
 gem 'rspec', '>= 3.7.0'
 gem 'rspec-collection_matchers'
 gem 'rspec-its'
-gem 'rubocop', '1.48'
+gem 'rubocop', '1.60.0'
 gem 'sqlite3'
 gem 'timecop'
 gem 'unparser'

lib/chewy/errors.rb

@@ -7,7 +7,7 @@ class UndefinedIndex < Error
 
   class UndefinedUpdateStrategy < Error
     def initialize(_type)
-      super <<-MESSAGE
+      super(<<-MESSAGE)
   Index update strategy is undefined for current context.
   Please wrap your code with `Chewy.strategy(:strategy_name) block.`
       MESSAGE
@@ -27,7 +27,7 @@ def initialize(type, import_errors)
           message << "        on #{documents.count} documents: #{documents}\n"
         end
       end
-      super message
+      super(message)
     end
   end
 

lib/chewy/rake_helper.rb

@@ -320,11 +320,7 @@ def indexes_from(only: nil, except: nil)
           all_indexes
         end
 
-        indexes = if except.present?
-          indexes - normalize_indexes(Array.wrap(except))
-        else
-          indexes
-        end
+        indexes -= normalize_indexes(Array.wrap(except)) if except.present?
 
         indexes.sort_by(&:derivable_name)
       end