Update Makefile

Co-authored-by: Danielle <dani@builds.terrible.systems>

Makefile

@@ -12,7 +12,7 @@ IMG ?= $(IMG_REPO):$(shell git rev-parse --short HEAD)-dev
 
 # Default registry and secret name for working with private container registries
 REGISTRY ?= $(shell echo "$(IMG)" | cut -d '/' -f 1)
-DEFAULT_REGISTRY_SECRET_NAME := registry-credentials
+REGISTRY_SECRET_NAME ?= registry-credentials
 
 # ENVTEST_K8S_VERSION refers to the version of kubebuilder assets to be downloaded by envtest binary.
 ENVTEST_K8S_VERSION = 1.28.3