Remove older JDK versions from GitHub Actions' matrix

Author: techncl

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-13, windows-latest]
-        jdk: [11, 17, 21]
+        jdk: [21]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4