Prune unsupported versions of go

.github/workflows/test.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: [ '1.20', '1.21', '1.22' ]
+        go: [ '1.22', '1.23' ]
     name: Test Go ${{ matrix.go }}
     steps:
       - uses: actions/setup-go@v5