ci.yml in zip_kit-6.3.1

- old
+ new

@@ -12,10 +12,10 @@
     runs-on: ubuntu-22.04
     strategy:
       matrix:
         ruby:
           - '2.6'
-          - '3.2'
+          - '3.3'
     steps:
       - name: Checkout
         uses: actions/checkout@v4
       - name: Setup Ruby
         uses: ruby/setup-ruby@v1