Don’t delete deploy key when user who created it is deleted

app/models/user.rb

@@ -82,11 +82,8 @@ class User < ActiveRecord::Base
   has_one :namespace, -> { where(type: nil) }, dependent: :destroy, foreign_key: :owner_id, inverse_of: :owner, autosave: true # rubocop:disable Cop/ActiveRecordDependent
 
   # Profile
-  has_many :keys, -> do
-    type = Key.arel_table[:type]
-    where(type.not_eq('DeployKey').or(type.eq(nil)))
-  end, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
-  has_many :deploy_keys, -> { where(type: 'DeployKey') }, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
+  has_many :keys, -> { where(type: ['Key', nil]) }, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
+  has_many :deploy_keys, -> { where(type: 'DeployKey') }, dependent: :nullify # rubocop:disable Cop/ActiveRecordDependent
   has_many :gpg_keys
 
   has_many :emails, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent

spec/models/user_spec.rb

@@ -25,7 +25,7 @@ describe User do
     it { is_expected.to have_many(:group_members) }
     it { is_expected.to have_many(:groups) }
     it { is_expected.to have_many(:keys).dependent(:destroy) }
-    it { is_expected.to have_many(:deploy_keys).dependent(:destroy) }
+    it { is_expected.to have_many(:deploy_keys).dependent(:nullify) }
     it { is_expected.to have_many(:events).dependent(:destroy) }
     it { is_expected.to have_many(:issues).dependent(:destroy) }
     it { is_expected.to have_many(:notes).dependent(:destroy) }