Test on 1.20. Stop testing on 1.18

Author: oschwald

.github/workflows/go.yml

@@ -8,7 +8,7 @@ jobs:
     name: Build
     strategy:
       matrix:
-        go-version: [1.18.x, 1.19.x]
+        go-version: [1.19.x, 1.20.x]
         platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps: