minor improvement to dev image builds

Makefile

@@ -1,13 +1,13 @@
 REPO_NAME ?= $(shell basename `git rev-parse --show-toplevel`)
 IMAGE_NAME ?= ghcr.io/cloudzero/cloudzero-agent-validator/cloudzero-agent-validator
-TAG ?= dev-$(git rev-parse --short HEAD)
 
 # Docker is the default container tool (and buildx buildkit)
 CONTAINER_TOOL ?= docker
 BUILDX_CONTAINER_EXISTS := $(shell $(CONTAINER_TOOL) buildx ls --format "{{.Name}}: {{.DriverEndpoint}}" | grep -c "container:")
 
 BUILD_TIME ?= $(shell date -u '+%Y-%m-%d_%I:%M:%S%p')
 REVISION ?= $(shell git rev-parse HEAD)
+TAG ?= dev-$(REVISION)
 
 # Directories
 # Colors