remove pinned redlock dependency

see `Gemfile`:

```ruby
# Locking "redlock" to < 2.0, as the 2.x series currently breaks Sidekiq jobs.
# @see https://github.com/samvera/hyrax/pull/5961
# @todo remove when Hyrax 3.5.1 or 3.6 (whichever includes it) drops
gem 'redlock', '>= 0.1.2', '< 2.0'
```