remove makefile for building container image (superseded by pipeline pushing to ghcr.io)

Makefile

@@ -1,41 +0,0 @@
-# sync with https://github.com/fphammerle/docker-onion-service/blob/master/Makefile
-
-IMAGE_NAME = docker.io/fphammerle/postfix
-PROJECT_VERSION = $(shell git describe --match=v* --abbrev=0 --dirty | sed -e 's/^v//')
-POSTFIX_PACKAGE_VERSION = $(shell grep -Po 'POSTFIX_PACKAGE_VERSION=\K.+' Dockerfile | tr -d -)
-ARCH = $(shell arch)
-# architecture[arm_variant]
-# https://github.com/opencontainers/image-spec/blob/v1.0.1/image-index.md#image-index-property-descriptions
-IMAGE_TAG_ARCH_aarch64 = arm64
-IMAGE_TAG_ARCH_armv6l = armv6
-IMAGE_TAG_ARCH_armv7l = armv7
-IMAGE_TAG_ARCH_x86_64 = amd64
-IMAGE_TAG_ARCH = ${IMAGE_TAG_ARCH_${ARCH}}
-MANIFEST_TAG = ${PROJECT_VERSION}-postfix${POSTFIX_PACKAGE_VERSION}
-IMAGE_TAG = ${MANIFEST_TAG}-${IMAGE_TAG_ARCH}
-BUILD_PARAMS = --tag="${IMAGE_NAME}:${IMAGE_TAG}" \
-	--build-arg=REVISION="$(shell git rev-parse HEAD)"
-
-.PHONY: worktree-clean docker-build podman-build docker-push docker-manifest-create docker-manifest-push
-
-worktree-clean:
-	git diff --exit-code
-	git diff --staged --exit-code
-
-docker-build: worktree-clean
-	sudo docker build ${BUILD_PARAMS} .
-
-podman-build: worktree-clean
-	# --format=oci (default) not fully supported by hub.docker.com
-	# https://github.com/docker/hub-feedback/issues/1871#issuecomment-748924149
-	podman build --format=docker ${BUILD_PARAMS} .
-
-docker-push: docker-build
-	sudo docker push "${IMAGE_NAME}:${IMAGE_TAG}"
-	@echo git tag --sign --message '$(shell sudo docker image inspect --format '{{join .RepoDigests "\n"}}' "${IMAGE_NAME}:${IMAGE_TAG}")' docker/${IMAGE_TAG} $(shell git rev-parse HEAD)
-
-docker-manifest-push:
-	git tag | grep '^docker/${MANIFEST_TAG}-' | xargs -L1 -t git tag -v \
-		| grep @sha256: | xargs -t sudo docker manifest create "${IMAGE_NAME}:${MANIFEST_TAG}"
-	sudo docker manifest push "${IMAGE_NAME}:${MANIFEST_TAG}"
-	sudo docker manifest inspect "${IMAGE_NAME}:${MANIFEST_TAG}" | yq --yaml-output .