Test against Ruby 3.3

.github/workflows/ci.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ '2.6', '2.7', '3.0', '3.1', '3.2' ]
+        ruby: [ '2.6', '2.7', '3.0', '3.1', '3.2', '3.3' ]
         rails: [ '5-2', '6-0', '6-1', '7-0' ]
         exclude:
           - ruby: 2.6 # Rails 7 requires 2.7 minimum
@@ -26,6 +26,12 @@ jobs:
             rails: 6-0
           - ruby: 3.2
             rails: 6-1
+          - ruby: 3.3 # Ruby 3.3 only works on the latest Rails 7 version
+            rails: 5-2
+          - ruby: 3.3
+            rails: 6-0
+          - ruby: 3.3
+            rails: 6-1
 
     steps:
       - uses: actions/checkout@v2