Modernize dependencies and fix CI

.rubocop.yml

@@ -1,3 +1,5 @@
+inherit_from: .rubocop_todo.yml
+
 # The behavior of RuboCop can be controlled via the .rubocop.yml
 # configuration file. It makes it possible to enable/disable
 # certain cops (checks) and to alter their behavior if they accept
@@ -8,6 +10,9 @@
 # where the inspected file is and continue its way up to the root directory.
 #
 # See https://docs.rubocop.org/rubocop/configuration
+plugins:
+  - rubocop-gusto
+
 AllCops:
   SuggestExtensions: false
   NewCops: enable

.rubocop_todo.yml

@@ -0,0 +1,51 @@
+# This configuration was generated by
+# `rubocop --auto-gen-config`
+# on 2026-03-05 18:26:56 UTC using RuboCop version 1.85.1.
+# The point is for the user to remove these configuration records
+# one by one as the offenses are removed from the code base.
+# Note that changes in the inspected code, or installation of new
+# versions of RuboCop, may require this file to be generated again.
+
+# Offense count: 3
+Gusto/NoMetaprogramming:
+  Exclude:
+    - 'test/support/test_macro.rb'
+
+# Offense count: 1
+Gusto/ToplevelConstants:
+  Exclude:
+    - 'test/test_helper.rb'
+
+# Offense count: 1
+# Configuration parameters: Mode, AllowedMethods, AllowedPatterns, AllowBangMethods, WaywardPredicates.
+# AllowedMethods: call
+# WaywardPredicates: infinite?, nonzero?
+Naming/PredicateMethod:
+  Exclude:
+    - 'lib/packwerk/privacy/checker.rb'
+
+# Offense count: 3
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Performance/StringInclude:
+  Exclude:
+    - 'bin/rake'
+    - 'bin/rubocop'
+    - 'bin/tapioca'
+
+# Offense count: 19
+# This cop supports safe autocorrection (--autocorrect).
+# Configuration parameters: SuggestedStrictness.
+Sorbet/FalseSigil:
+  Enabled: false
+
+# Offense count: 45
+# This cop supports unsafe autocorrection (--autocorrect-all).
+# Configuration parameters: SuggestedStrictness.
+Sorbet/StrictSigil:
+  Enabled: false
+
+# Offense count: 1
+# This cop supports unsafe autocorrection (--autocorrect-all).
+Style/FileNull:
+  Exclude:
+    - 'test/rails_test_helper.rb'

Gemfile

@@ -3,5 +3,3 @@
 source 'https://rubygems.org'
 
 gemspec
-
-gem 'packwerk', git: 'https://github.com/Shopify/packwerk', branch: 'main'