Update tests.yml

Author: xuanxu

.github/workflows/tests.yml

@@ -7,10 +7,10 @@ jobs:
     continue-on-error: ${{ matrix.failure-allowed }}
     strategy:
       matrix:
-        ruby-version: ['3.2', '3.3', '3.4', '4.0']
+        ruby-version: ['3.2', '3.3', '3.4']
         failure-allowed: [false]
         include:
-        - ruby-version: 'truffleruby'
+        - ruby-version: '4.0'
           failure-allowed: true
     steps:
     - uses: actions/checkout@v4