PERF: introduce a basic api key serializer

For better performances when listing all the API keys.

Loading all the "api key scopes" is slow and not required when showing the list of all the api keys.

app/controllers/admin/api_controller.rb

@@ -13,12 +13,16 @@ class Admin::ApiController < Admin::AdminController
     keys =
       ApiKey
         .where(hidden: false)
-        .includes(:user, :api_key_scopes)
+        .includes(:user)
         .order("revoked_at DESC NULLS FIRST, created_at DESC")
         .offset(offset)
         .limit(limit)
 
-    render_json_dump(keys: serialize_data(keys, ApiKeySerializer), offset: offset, limit: limit)
+    render_json_dump(
+      keys: serialize_data(keys, BasicApiKeySerializer),
+      offset: offset,
+      limit: limit,
+    )
   end
 
   def show

app/serializers/basic_api_key_serializer.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class BasicApiKeySerializer < ApplicationSerializer
+  attributes :id, :truncated_key, :description, :created_at, :last_used_at, :revoked_at
+
+  has_one :user, serializer: BasicUserSerializer, embed: :objects
+end