use stable/oldstable over specific Go versions

Author: bitfield

.github/workflows/test.yml

@@ -5,7 +5,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.19.x, 1.20.x]
+        go-version: ['stable', 'oldstable']
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps: