Adapt some tests to pass both in Ruby 3.1 and Ruby 3.2
What does this MR do and why?
- Avoid using predicate matcher in helper specs
- It doesn't work due to a bug in Rails' ActionView, so it can't be used for now. Even though the PR has been merged: https://github.com/rails/rails/pull/48667, it will require some time to get it to GitLab Rails
- Accept only strings for hex color helpers
- The following code raises NoMethodError now instead or nil:
[] =~ /regex/ 1 =~ /regex/
- The following code raises NoMethodError now instead or nil:
- Modify regexp in specs to match error messages in Ruby 3.1 and 3.2
- Propagate kwarg correctly for pipeline_cleanup_ref_worker_spec