Bump rubocop from 1.57.2 to 1.58.0 and fix offenses

Bumps [rubocop](https://github.com/rubocop/rubocop) from 1.57.2 to 1.58.0.
- [Release notes](https://github.com/rubocop/rubocop/releases)
- [Changelog](https://github.com/rubocop/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop/rubocop/compare/v1.57.2...v1.58.0)

---
updated-dependencies:
- dependency-name: rubocop
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

app/controllers/concerns/lti.rb

@@ -229,7 +229,7 @@ module Lti
        hide_test_results
        disable_hints
        disable_download].each do |option|
-      value = params["custom_embed_options_#{option}".to_sym] == 'true'
+      value = params[:"custom_embed_options_#{option}"] == 'true'
       # Optimize storage and save only those that are true, the session cookie is limited to 4KB
       @embed_options[option] = value if value.present?
     end

app/controllers/tips_controller.rb

@@ -28,7 +28,7 @@ class TipsController < ApplicationController
 
     params[:tip]
       .permit(:title, :description, :example, :file_type_id)
-      .each {|_key, value| value.strip! unless value.is_a?(Array) }
+      .each_value {|value| value.strip! unless value.is_a?(Array) }
       .merge(user: current_user)
   end
   private :tip_params