Use protoImage for buf calls

Makefile

@@ -10,8 +10,6 @@ SIMAPP = ./app
 
 # for dockerized protobuf tools
 DOCKER := $(shell which docker)
-BUF_IMAGE=bufbuild/buf@sha256:3cb1f8a4b48bd5ad8f09168f10f607ddc318af202f5c057d52a45216793d85e5 #v1.4.0
-DOCKER_BUF := $(DOCKER) run --rm -v $(CURDIR):/workspace --workdir /workspace $(BUF_IMAGE)
 HTTPS_GIT := https://github.com/CosmWasm/wasmd.git
 
 export GO111MODULE = on
@@ -187,10 +185,10 @@ proto-swagger-gen:
 	@./scripts/protoc-swagger-gen.sh
 
 proto-lint:
-	@$(DOCKER_BUF) lint --error-format=json
+	@$(protoImage) buf lint --error-format=json
 
 proto-check-breaking:
-	@$(DOCKER_BUF) breaking --against $(HTTPS_GIT)#branch=main
+	@$(protoImage) buf breaking --against $(HTTPS_GIT)#branch=main
 
 .PHONY: all install install-debug \
 	go-mod-cache draw-deps clean build format \