Fix podman multiarch build

Dockerfile

@@ -1,11 +1,9 @@
-# We do not use --platform feature to auto fill this ARG because of incompatibility between podman and docker
-ARG TARGETPLATFORM=linux/amd64
-ARG BUILDPLATFORM=linux/amd64
+ARG TARGETARCH
+
 # Build the manager binary
-FROM --platform=$BUILDPLATFORM docker.io/library/golang:1.22 as builder
+FROM docker.io/library/golang:1.22 as builder
 ARG BUILD_VERSION="unknown"
 
-ARG TARGETPLATFORM
 ARG TARGETARCH=amd64
 WORKDIR /opt/app-root
 
@@ -23,7 +21,7 @@ COPY config/ config/
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=$TARGETARCH GO111MODULE=on go build -ldflags "-X 'main.buildVersion=$BUILD_VERSION' -X 'main.buildDate=`date +%Y-%m-%d\ %H:%M`'" -mod vendor -a -o manager main.go
 
 # Create final image from minimal + built binary
-FROM --platform=$TARGETPLATFORM registry.access.redhat.com/ubi9/ubi-minimal:9.4
+FROM --platform=linux/$TARGETARCH registry.access.redhat.com/ubi9/ubi-minimal:9.4
 WORKDIR /
 COPY --from=builder /opt/app-root/manager .
 USER 65532:65532

Makefile

@@ -127,7 +127,7 @@ include .bingo/Variables.mk
 # build a single arch target provided as argument
 define build_target
 	echo 'building image for arch $(1)'; \
-	DOCKER_BUILDKIT=1 $(OCI_BIN) buildx build --load --build-arg TARGETPLATFORM=linux/$(1) --build-arg TARGETARCH=$(1) --build-arg BUILDPLATFORM=linux/amd64 ${OCI_BUILD_OPTS} -t ${IMAGE}-$(1) -f Dockerfile .;
+	DOCKER_BUILDKIT=1 $(OCI_BIN) buildx build --load --build-arg TARGETARCH=$(1) ${OCI_BUILD_OPTS} -t ${IMAGE}-$(1) -f Dockerfile .;
 endef
 
 # push a single arch target image