Fix incorrect deprecation warning for DELETE /api/v1/suggestions/:id (#34397)

app/controllers/api/v1/suggestions_controller.rb

@@ -4,7 +4,7 @@ class Api::V1::SuggestionsController < Api::BaseController
   include Authorization
   include DeprecationConcern
 
-  deprecate_api '2021-05-16'
+  deprecate_api '2021-05-16', only: [:index]
 
   before_action -> { doorkeeper_authorize! :read, :'read:accounts' }, only: :index
   before_action -> { doorkeeper_authorize! :write, :'write:accounts' }, except: :index