Stop testing with EL7 as it is no longer supported

Tests fail as the containers are no longer working. This commit removes
EL7 from the list of platforms that receive acceptance testing.

Author: ghoneycutt

.github/workflows/ci.yaml

@@ -60,7 +60,6 @@ jobs:
           - "debian-11"
           - "ubuntu-2004"
           - "ubuntu-2204"
-          - "el7"
         puppet:
           - "puppet7"
           - "puppet8"

.sync.yml

@@ -9,7 +9,6 @@
 .github/workflows/ci.yaml:
   acceptance_matrix:
     set:
-      - el7
       - el8
       - el9
       - debian-11