rpm: fix missing GOTOOLCHAIN=local in centos, rhel Dockerfiles

Commit a4090a0 added GOTOOLCHAIN=local,
but for some reason missed the centos Dockerfiles.

The env-var is set to make sure we don't get unexpected updates of the go
toolchain when building. We need to set this env-var, because we're not using
the official golang image as base-image, but instead copy the binaries into
a distro-image.

This patch adds the missing GOTOOLCHAIN env-vars.

Signed-off-by: Sebastiaan van Stijn <[email protected]>

Author: thaJeztah

rpm/centos-9/Dockerfile

@@ -11,6 +11,7 @@ FROM ${BUILD_IMAGE}
 ENV GOPROXY=https://proxy.golang.org|direct
 ENV GO111MODULE=off
 ENV GOPATH=/go
+ENV GOTOOLCHAIN=local
 ENV PATH $PATH:/usr/local/go/bin:$GOPATH/bin
 ENV AUTO_GOPATH 1
 ENV DOCKER_BUILDTAGS exclude_graphdriver_btrfs

rpm/rhel-8/Dockerfile

@@ -28,6 +28,7 @@ FROM subscribed-image
 ENV GOPROXY=https://proxy.golang.org|direct
 ENV GO111MODULE=off
 ENV GOPATH=/go
+ENV GOTOOLCHAIN=local
 ENV PATH $PATH:/usr/local/go/bin:$GOPATH/bin
 ENV AUTO_GOPATH 1
 ENV DOCKER_BUILDTAGS exclude_graphdriver_btrfs

rpm/rhel-9/Dockerfile

@@ -28,6 +28,7 @@ FROM subscribed-image
 ENV GOPROXY=https://proxy.golang.org|direct
 ENV GO111MODULE=off
 ENV GOPATH=/go
+ENV GOTOOLCHAIN=local
 ENV PATH $PATH:/usr/local/go/bin:$GOPATH/bin
 ENV AUTO_GOPATH 1
 ENV DOCKER_BUILDTAGS exclude_graphdriver_btrfs