remove variable from makefile

Author: pdabelf5

tests/Makefile

@@ -22,7 +22,6 @@ K8S_CLUSTER_NAME            ?= local ## The name used when creating/using a Kin
 # renovate: datasource=docker depName=kindest/node
 K8S_CLUSTER_VERSION         ?= v1.34.0
 K8S_TIMEOUT                 ?= 75s ## The timeout used when creating a Kind Kubernetes cluster
-AD_SECRET                   ?=
 PLUS_JWT                    ?=
 PYTEST_ARGS                 ?=
 ifeq (${REGISTRY},)