test helper: adjusted unit tests using new features (#9563)

tests/unit/plugins/modules/test_facter_facts.yaml

@@ -4,6 +4,9 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 ---
+anchors:
+  environ: &env-def {check_rc: true}
+test_cases:
 - id: simple run
   output:
     ansible_facts:
@@ -14,7 +17,7 @@
   mocks:
     run_command:
     - command: [/testbin/facter, --json]
-      environ: &env-def {check_rc: true}
+      environ: *env-def
       rc: 0
       out: >
         { "a": 1, "b": 2, "c": 3 }