Fixes Rails/UnknownEnv offense

- Cop: Rails/UnknownEnv
- Cf. https://docs.rubocop.org/rubocop-rails/cops_rails.html#railsunknownenv
- Rails.env.typo? will always return false and will not return an error
- The way to check this is to add environments in the Environments config parameter
- in the rubocop file.

.rubocop_styleguide.yml

@@ -129,6 +129,13 @@ Rails/SkipsModelValidations:
     - update_column
     - update_columns
 
+Rails/UnknownEnv:
+  Environments:
+    - development
+    - production
+    - staging
+    - test
+
 Rails/WhereExists:
   EnforcedStyle: where # Cf. conversion https://github.com/openfoodfoundation/openfoodnetwork/pull/12363
 

.rubocop_todo.yml

@@ -693,13 +693,6 @@ Rails/UniqueValidationWithoutIndex:
     - 'app/models/spree/tax_category.rb'
     - 'app/models/spree/zone.rb'
 
-# Offense count: 1
-# Configuration parameters: Severity, Environments.
-# Environments: development, test, production
-Rails/UnknownEnv:
-  Exclude:
-    - 'app/models/spree/app_configuration.rb'
-
 # Offense count: 1
 Security/Open:
   Exclude: