Running in Go 1.20 only

Author: oxisto

.github/workflows/build.yml

@@ -25,7 +25,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go: [1.17, 1.18, 1.19]
+        go: ["1.20"]
     steps:
       - name: Checkout
         uses: actions/checkout@v3