Upgrade to rubocop 1.60.0 and rubocop-rails 2.23.1

[foobear]

Upgrade to support Ruby 3.3 and Rails 7.1.

Newly introduced cops

The upgrade introduces several new cops.

All of them were set to Enabled: pending in the default Rubocop configuration. Since we set NewCops: enable this means all pending cops are enabled, i.e. the same as if we'd explicitly set them to Enabled: true. We do not want to set Enabled: true for all of them to avoid merge conflicts when upgrading later.

I reviewed all new cops and disabled those which I believe do not provide enough benefit and/or do not match our preferred code styles:

• Metrics/CollectionLiteralLength because doing what this cop disallows can be useful for seeding data; in such cases, introducing a separate file would barely improve anything. In "regular" application code nobody would do what that cop tries to cover, so we should not enforce it by default.
• Style/ConcatArrayLiterals as it can be more readable to concat array(s) literals onto another array instead of pushing individual elements. The potential performance difference (virtually always insignificant, since this is about array literals) is IMO not worth enforcing push in such cases.
• Style/DataInheritance because we also disabled Style/StructInheritance in our default config.
• ~Style/MinMaxComparison since there are valid reasons to do comparison over min/max, e.g. for readability. IMO not worth the noise the cop produces.~
• In Style/ArgumentsForwarding, UseAnonymousForwarding: false has been set since I believe enforcing * and ** does neither match our existing code style nor does it improve code readability (rather the contrary).
• Rails/RedundantActiveRecordAllMethod (from rubocop-rails) While we agree that User.all.find is redundant, it can be useful to make relation access more explicit for other query methods.

Warning from Style/ArgumentsForwarding cop

Annoyingly, in a Ruby 3.3 application, Rubocop prints a warning:

Warning: obsolete parameter `AllowOnlyRestArgument` (for `Style/ArgumentsForwarding`) found in .../config/default.yml
`AllowOnlyRestArgument` has no effect with TargetRubyVersion >= 3.2.

I am not sure how to resolve that properly. The parameter is also included in the default configuration, so I assume that is just how Rubocop behaves when it's set from another file. When removing it from our default.yml, Rubocop will not print the warning, but I don't know if its default AllowOnlyRestArgument: true still applies. Maybe we don't need to care. Instead of removing that line, we could comment it out and leave a comment about why. Would help with future upgrades.

Jan 3 update: I went ahead with commenting out the AllowOnlyRestArgument option and left a comment explaining why.

What about rubocop-rspec?

I did not upgrade rubocop-rspec as there seem to be some configuration changes between rubocop-rspec and rubocop-capybara now. Did not investigate further.

[foobear]

Reverted disabling Style/MinMaxComparison, it's now explicitly enabled.

Rubocop 1.60.0 has been released on Monday; I'll look into upgrading to 1.60.0 now.

[foobear]

Upgraded to 1.16.0, fixed some quirks in previous commits and prepared changelog.

Will merge and release as version 12.0.0.