RuboCop dual config

[JoeCohen]

• Adds 2nd RuboCop config file, used only by CodeClimate, which loads plugins with require
• Tells CodeClimate GitHub App to use that file to configure RuboCop
• Changes local (default) RuboCop config file to load extensions with plugins
• Fixes CodeClimate CI error which was caused by using plugins. Ex: https://codeclimate.com/github/MushroomObserver/mushroom-observer/builds/11148
• Result:
  • We can use RuboCop >= 1.72 locally
  • CodeClimate CI works

[coveralls]

coverage: 93.504%. remained the same
when pulling 0df809f on jdc-rubocop-dual-config
into 1f146d3 on main.

[JoeCohen]

@mo-nathan & @nimmolo
This is an alternative to freezing the RuboCop version.
I'd mostly like your opinion whether it's the better alternative.

[JoeCohen]

Advantage:

• We can use RuboCop >= 1.72, so we get bug fixes as well as newer cops.
  Disadvantage:
• The local Rubocop version is different from the Codeclimate CI version. (Looks to me like CI will be stuck on 1.71 unless/until Codeclimate updates its Rubocop "channel".)

[JoeCohen]

I added:

• an Issue to CodeClimate RuboCop 1.72 breaks GitHub CodeClimate CI codeclimate/codeclimate-rubocop#376
• an Issue to RuboCop RuboCop 1.72 breaks GitHub CodeClimate CI rubocop/rubocop#13934

I also contact CodeClimate directly via their support form.

[JoeCohen]

Closing. Replaced by #2828.