chore(ci): prevent deprecated custom runner from being used (#4061)

* fix(parameters): make cache aware of single vs multiple calls

Signed-off-by: heitorlessa <lessa@amazon.co.uk>

* chore: cleanup, add test for single and nested

Signed-off-by: heitorlessa <lessa@amazon.co.uk>

* chore(ci): prevent usage of deprecated custom runner

---------

Signed-off-by: heitorlessa <lessa@amazon.co.uk>

Author: heitorlessa

.github/actionlint.yaml

@@ -1,4 +1,3 @@
 self-hosted-runner:
   labels:
-    - aws-powertools_ubuntu-latest_4-core 
     - aws-powertools_ubuntu-latest_8-core