Revert "Make parent_validations work"

This reverts commit efab9bd02d6a962641bbdb7d53c63091e1299356.

lib/gitlab/ci/config/entry/jobs.rb

@@ -11,6 +11,8 @@ module Gitlab
           include ::Gitlab::Config::Entry::Validatable
 
           validations do
+            validates :config, type: Hash
+
             validate do
               each_unmatched_job do |name|
                 errors.add(name, 'config should implement a script: or a trigger: keyword')

lib/gitlab/config/entry/composable_hash.rb

@@ -10,13 +10,11 @@ module Gitlab
       class ComposableHash < ::Gitlab::Config::Entry::Node
         include ::Gitlab::Config::Entry::Validatable
 
-        def self.parent_validations
+        # TODO: Refactor Validatable so these validations will not apply to a child class
+        # See: https://gitlab.com/gitlab-org/gitlab/-/issues/263231
         validations do
           validates :config, type: Hash
         end
-        end
-
-        parent_validations
 
         def compose!(deps = nil)
           super do

lib/gitlab/config/entry/node.rb

@@ -20,8 +20,6 @@ module Gitlab
 
           yield(self) if block_given?
 
-          self.class.parent_validations if self.class.respond_to?(:parent_validations)
-          
           self.class.aspects.to_a.each do |aspect|
             instance_exec(&aspect)
           end

lib/gitlab/config/entry/validatable.rb

@@ -39,6 +39,8 @@ module Gitlab
             end
           end
 
+          private
+
           def validations(&block)
             (@validations ||= []).append(block)
           end