ci: add latest version of terraform

Author: fabiomatavelli

.github/workflows/acceptance.yml

@@ -97,18 +97,10 @@ jobs:
       fail-fast: false
       matrix:
         terraform-version:
-          - '0.12.*'
-          - '0.13.*'
-          - '0.14.*'
-          - '0.15.*'
-          - '1.0.*'
-          - '1.1.*'
-          - '1.2.*'
-          - '1.3.*'
-          - '1.4.*'
           - '1.5.*'
           - '1.6.*'
           - '1.7.*'
+          - '1.8.*'
         cloudstack-version:
           - 4.17.2.0
           - 4.18.1.0