[0.8] generated files: use "go install" to install binaries

Now that this repository moved to go1.16, we can use 'go install' to install
these binaries.

based on commit bd4b02d
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

hack/dockerfiles/generated-files.Dockerfile

@@ -2,24 +2,24 @@
 
 # protoc is dynamically linked to glibc to can't use golang:1.10-alpine
 FROM golang:1.13-buster AS gobuild-base
-ARG PROTOC_VERSION=3.1.0
-ARG GOGO_VERSION=master
+
 RUN apt-get update && apt-get --no-install-recommends install -y \
 	git \
 	unzip \
 	&& true
+
+ARG PROTOC_VERSION=3.1.0
 RUN wget -q https://github.com/google/protobuf/releases/download/v${PROTOC_VERSION}/protoc-${PROTOC_VERSION}-linux-x86_64.zip && unzip protoc-${PROTOC_VERSION}-linux-x86_64.zip -d /usr/local
 
-RUN go get -d github.com/gogo/protobuf/protoc-gen-gogofaster \
-	&& cd /go/src/github.com/gogo/protobuf \
-	&& git checkout -q $GOGO_VERSION \
-	&& go install ./protoc-gen-gogo ./protoc-gen-gogofaster ./protoc-gen-gogoslick
+ARG GOGO_VERSION=v1.3.2
+RUN --mount=target=/root/.cache,type=cache GO111MODULE=on go install \
+	github.com/gogo/protobuf/protoc-gen-gogo@${GOGO_VERSION} \
+	github.com/gogo/protobuf/protoc-gen-gogofaster@${GOGO_VERSION} \
+	github.com/gogo/protobuf/protoc-gen-gogoslick@${GOGO_VERSION}
 
 ARG PROTOBUF_VERSION=v1.3.3
-RUN go get -d github.com/golang/protobuf/protoc-gen-go \
-	&& cd /go/src/github.com/golang/protobuf \
-	&& git checkout -q $PROTOBUF_VERSION \
-	&& go install ./protoc-gen-go
+RUN --mount=target=/root/.cache,type=cache GO111MODULE=on go install \
+	github.com/golang/protobuf/protoc-gen-go@${PROTOBUF_VERSION}
 
 WORKDIR /go/src/github.com/moby/buildkit