Minor rubocop updates

.rubocop.yml

@@ -239,7 +239,11 @@ Performance/Squeeze:
 Performance/StringInclude:
   Enabled: true
 
+Performance/MethodObjectAsBlock:
+  Enabled: false
   
+Performance/BlockGivenWithExplicitBlock:
+  Enabled: false
 
 RSpec/ExampleWording:
   Enabled: false

lib/capybara/result.rb

@@ -39,7 +39,7 @@ module Capybara
     alias index find_index
 
     def each(&block)
-      return enum_for(:each) unless block_given?
+      return enum_for(:each) unless block
 
       @result_cache.each(&block)
       loop do

lib/capybara/rspec/matcher_proxies.rb

@@ -11,7 +11,7 @@ module Capybara
     end
 
     def within(*args, **kwargs, &block)
-      if block_given?
+      if block
         within_element(*args, **kwargs, &block)
       else
         be_within(*args)

lib/capybara/selector/definition.rb

@@ -178,7 +178,7 @@ module Capybara
       def_delegator :@filter_set, :describe
 
       def describe_expression_filters(&block)
-        if block_given?
+        if block
           describe(:expression_filters, &block)
         else
           describe(:expression_filters) do |**options|

lib/capybara/session.rb

@@ -489,8 +489,8 @@ module Capybara
     # @raise [ArgumentError]               if both or neither arguments were provided
     #
     def switch_to_window(window = nil, **options, &window_locator)
-      raise ArgumentError, '`switch_to_window` can take either a block or a window, not both' if window && block_given?
-      raise ArgumentError, '`switch_to_window`: either window or block should be provided' if !window && !block_given?
+      raise ArgumentError, '`switch_to_window` can take either a block or a window, not both' if window && window_locator
+      raise ArgumentError, '`switch_to_window`: either window or block should be provided' if !window && !window_locator
 
       unless scopes.last.nil?
         raise Capybara::ScopeError, '`switch_to_window` is not supposed to be invoked from '\