The cop is detecting calls to all on any object, not just ActiveRecord models. Using RSpec and Capybara, it can be useful to write code like:

page.all("button").select(&custom_filter).first.click

This is detected by the cop even though all and first do not refer to ActiveRecord methods.

Expected behavior

The cop should only complain about ActiveRecord's all method.

Actual behavior

spec/system/consumer/shopping/shopping_spec.rb:564:20: C: [Correctable] Rails/RedundantActiveRecordAllMethod: Redundant all detected.
              page.all("button", text: increase_quantity_symbol).last.click
                   ^^^

Steps to reproduce the problem

echo '
describe "failing cop", type: :system do
  it "detects Capybara calls" do
    page.all("button").first
  end
end
' > example_spec.rb

rubocop example_spec.rb

RuboCop version

Include the output of rubocop -V or bundle exec rubocop -V if using Bundler. Here's an example:
You can see extension cop versions (e.g. rubocop-rails, rubocop-performance, and others) output by rubocop -V,
include them as well. Here's an example:

$ [bundle exec] rubocop -V
1.56.2 (using Parser 3.2.2.3, rubocop-ast 1.29.0, running on ruby 3.1.4) [x86_64-linux]
  - rubocop-rails 2.21.0