Fixes #37852 - Support Rails 7.0

[ofedoren]

What are the changes introduced in this pull request?

We're updating Rails version in Foreman: theforeman/foreman#10299 (please visit it first if you have any questions/suggestions, there are many comments regarding the changes)

This PR tries to make Katello Rails 7 friendly (compatible).

Considerations taken when implementing this change?

1. Mostly removing deprecated usage of #<< for ActiveModel::Errors objects
2. Just a heads up regarding https://guides.rubyonrails.org/upgrading_ruby_on_rails.html#digest-class-for-activesupport-digest-changing-to-sha256. How it affects this plugin is more or less here: Fixes #37825 - Upgrade Rails to 7.0 theforeman/foreman#10299 (comment)

What are the testing steps for this pull request?

Ensuring CI is green.

If you really want some 🍪, test some workflows live.

[ekohl]

I see lots of changes around the error handling and I think that's already Rails 6.1 compatible. Perhaps something that we can already merge to reduce the size of this PR?

[ekohl]

Suggested change

	assert_empty @content_facet.errors.map { |error| error.message }
	assert_empty @content_facet.errors.map(&:message)

[chris1984]

@SatelliteQE/TeamPhoenix

[Satellite-QE]

PRT Result

Build Number: 9132
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman --team Phoenix-content --external-logging
Test Result: = 6 skipped, 3973 deselected, 5492 warnings, 1490 errors in 4906.50s (1:21:46) =

[Satellite-QE]

PRT Result

Build Number: 9133
Build Status: UNSTABLE
PRT Comment: pytest tests/foreman --team Phoenix-subscriptions --external-logging
Test Result: ======= 4779 deselected, 5492 warnings, 690 errors in 4923.46s (1:22:03) =======

[ekohl]

@chris1984 I doubt PRT is going to be of any use. You need updated Foreman and Rails and we haven't packaged that.

[ofedoren]

The test failure is unrelated to this PR, it for some reason wasn't caught by GHA for theforeman/foreman_remote_execution#913

Fixed in theforeman/foreman_remote_execution#925