Update Java test matrix (#1742)

Author: trask

.github/workflows/build.yml

@@ -43,7 +43,8 @@ jobs:
           - 8
           - 11
           - 17
-          - 20
+          - 21
+          - 23
       fail-fast: false
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2