[ci] use stable and oldstable identifiers (#187)

Signed-off-by: Jeroen Simonetti <[email protected]>

Author: jsimonetti

.github/workflows/go-test.yml

@@ -5,7 +5,7 @@ jobs:
     name: Test MacOS
     strategy:
       matrix:
-        go-version: [1.20.x, 1.21.x]
+        go-version: ['oldstable', 'stable']
         platform: [macos-latest]
     runs-on: ${{ matrix.platform }}
     steps:
@@ -33,7 +33,7 @@ jobs:
     name: Test Linux Integration
     strategy:
       matrix:
-        go-version: [1.20.x, 1.21.x]
+        go-version: ['oldstable', 'stable']
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: