cleanup workflow

Author: chernser

.github/workflows/test_head.yml

@@ -79,7 +79,7 @@ jobs:
       - name: Set up JDK
         uses: actions/setup-java@v4
         with:
-          java-version: '8'
+          java-version: '17'
           distribution: 'temurin'
           architecture: x64
       - name: Test R2DBC ${{ matrix.r2dbc }}