Bump rubocop TargetRubyVersion

Library/.rubocop.yml

@@ -18,10 +18,7 @@ inherit_mode:
     - Exclude
 
 AllCops:
-  # TODO: This is the default parser in Ruby >= 3.4
-  # https://github.com/rubocop/rubocop-ast/blob/6b9136235219e9448ee4f369e17cf69bcd9db621/lib/rubocop/ast/processed_source.rb#L385
-  ParserEngine: parser_prism
-  TargetRubyVersion: 3.3
+  TargetRubyVersion: 3.4
   NewCops: enable
   Include:
     - "**/*.rbi"
@@ -412,6 +409,10 @@ Style/InvertibleUnlessCondition:
     :zero?:
     :blank?: :present?
 
+# Reconsider once sorbet supports "it": https://github.com/sorbet/sorbet/issues/8375
+Style/ItBlockParameter:
+  Enabled: false
+
 Style/MutableConstant:
   # would rather freeze too much than too little
   EnforcedStyle: strict