False positive for Rails/ActionControllerFlashBeforeRender when using return redirect_to

[ccutrer]

Expected behavior

When exiting an action early, we often use return redirect_to ..., since the return value doesn't matter, and it saves a line. Unfortunately, this can trigger an offense.

Actual behavior

app/controllers/gradebooks_controller.rb:1038:7: C: Rails/ActionControllerFlashBeforeRender: Use flash.now before render.
      flash[:notice] = t(:speed_grader_disabled, "SpeedGrader is disabled for this course")
      ^^^^^

Steps to reproduce the problem

    unless @context.allows_speed_grader?
      flash[:notice] = t(:speed_grader_disabled, "SpeedGrader is disabled for this course")
      return redirect_to(course_gradebook_path(@context))
    end

RuboCop version

% rubocop -V
1.61.0 (using Parser 3.3.0.5, rubocop-ast 1.31.1, running on ruby 3.1.3) [arm64-darwin21]
  - rubocop-factory_bot 2.25.1
  - rubocop-graphql 1.5.0
  - rubocop-performance 1.20.2
  - rubocop-rails 2.23.1
  - rubocop-rake 0.6.0
  - rubocop-rspec 2.27.0