ci: test on go1.13.x, oldstable, stable

Test the oldest version supported by the module, and currently
supported versions.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

.github/workflows/ci.yaml

@@ -18,7 +18,7 @@ jobs:
     timeout-minutes: 10
     strategy:
       matrix:
-        go-version: [1.13.x, 1.21.x, 1.22.x]
+        go-version: [1.13.x, oldstable, stable]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: