Append the correct targetarch to the filename

Dockerfile

@@ -4,5 +4,6 @@ COPY go.mod go.sum ./
 RUN go mod download && go mod verify
 COPY . .
 RUN make build \
- && mv bin/manager /
+ && mv bin/manager /manager_amd64 \
+ && ln -s /manager_amd64 /manager
 ENTRYPOINT ["/manager"]