Add Ruby 3.4 and 4.0 to test matrix

Author: justincase

.github/workflows/build.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3']
+        ruby-version: ['2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3', '3.4', '4.0']
 
     name: Ruby (${{ matrix.ruby-version }})
     steps: