(gh-29) Fix matrix to allow for other platforms

The simple cross product would breakdown the moment we add another
platform like Debian or Rocky, since it would cross all versions with
all platforms leading to curious os version combinations...

Author: jpartlow

.github/workflows/acceptance.yaml

@@ -51,21 +51,19 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu
-        os-version:
-          - '18.04'
-          - '20.04'
-          - '22.04'
-          - '24.04'
+          - [ubuntu, '18.04']
+          - [ubuntu, '20.04']
+          - [ubuntu, '22.04']
+          - [ubuntu, '24.04']
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - id: vm-cluster
         uses: jpartlow/kvm_automation_tooling@main
         with:
-          os: ${{ matrix.os }}
-          os-version: ${{ matrix.os-version }}
+          os: ${{ matrix.os[0] }}
+          os-version: ${{ matrix.os[1] }}
           os-arch: x86_64
           host-root-access: true
           ruby-version: ${{ env.RUBY_VERSION }}