fix: test on ruby 3.3 in gitlab

.gitlab-ci.yml

@@ -1,11 +1,9 @@
-include:
-  - project: "nstmrt/rubygems/templates"
-    ref: master
-    file: "build-rubygems.yml"
+stages:
+  - test
 
 lint:
   stage: test
-  image: ruby:3.2
+  image: ruby:3.3
   script:
     - bundle install
     - bundle exec rubocop
@@ -15,9 +13,9 @@ tests:
   image: ruby:$RUBY_VERSION
   parallel:
     matrix:
-      - RUBY_VERSION: ['2.7', '3.0', '3.1', '3.2']
+      - RUBY_VERSION: ['2.7', '3.0', '3.1', '3.2', '3.3']
   services:
-    - name: postgres:12.2
+    - name: postgres:13
       alias: postgres
     - name: redis:7
       alias: redis