change Dockerfile, introduce separate build step

Dockerfile

@@ -1,15 +1,8 @@
-FROM golang:1.22.5-alpine3.20 as builder
-
-RUN mkdir -p /go/src
-COPY ./src/ /go/src
-WORKDIR /go/src/udi
-RUN go build -a -installsuffix nocgo -o udi main.go
-
-
 FROM scratch
 
 ENV UDI_CONF ""
 
-COPY --from=builder /go/src/udi ./
+COPY udi ./
+
 ENTRYPOINT ["./udi"]