[WIP] Upgrade config to latest 5.x version for rails 7.1 compatibility

[jrafanie]

WIP, depends on:

• [x] https://github.com/ManageIQ/manageiq-api/pull/1275

I noticed deep_merge was behaving differently in tests and failing on 7.1.

Digging in, rails 7.0 was using the gem, 7.1 was using the activesupport module:

rails 7.1:

(byebug) {}.method(:deep_merge)
  #<Method: Hash(DeepMerge::DeepMergeHash)#deep_merge(source, options=...) /Users/joerafaniello/.gem/ruby/3.3.6/gems/deep_merge-1.2.2/lib/deep_merge/deep_merge_hash.rb:18>

rails 7.0:

(byebug) {}.method(:deep_merge)
  #<Method: Hash#deep_merge(other_hash, &block) /Users/joerafaniello/.gem/ruby/3.3.6/gems/activesupport-7.0.8.6/lib/active_support/core_ext/hash/deep_merge.rb:18>

Rails 7.1 changed the way their deep_merge is defined via a refactored module: https://www.github.com/rails/rails/commit/43b980368a7628fac95cc4f673e0dfbcee77c10b

This was raised in: https://www.github.com/rails/rails/issues/49457

Config gem fixed this in 5.0 and subsequently fixed another compatibility issue in 5.1 https://www.github.com/rubyconfig/config/commit/759c0fe271b4b90d534217a5b6e0653d0c94ee85

[jrafanie]

@miq-bot cross-repo-tests /all

[Fryguy]

This feels like it will could bite us in more places, but I have no idea how to find it. cc @agrare