switch to GCP

Author: LukasAud

.github/workflows/ci.yml

@@ -16,4 +16,4 @@ jobs:
     uses: "puppetlabs/cat-github-actions/.github/workflows/module_acceptance.yml@MAINT-GCP_troubleshooting"
     secrets: "inherit"
     with:
-      flags: "--nightly --platform-include=sles-15"
+      flags: "--nightly --platform-include=sles-12"