Normalize Welsh (#8538)

config/locales/activerecord.cy.yml

 ---
 cy:
-  activerecord:
+  activerecord: {}

config/locales/devise.cy.yml

 ---
 cy:
-  devise:
+  devise: {}

config/locales/doorkeeper.cy.yml

 ---
 cy:
-  doorkeeper:
+  doorkeeper: {}

config/locales/simple_form.cy.yml

 ---
 cy:
-  simple_form:
+  simple_form: {}