fix: update skopeo to latest

Author: ivanstanev

Dockerfile

@@ -1,22 +1,25 @@
 #---------------------------------------------------------------------
-# STAGE 1: Build skopeo and ecr-credentials-helper inside a temporary container
+# STAGE 1: Build skopeo inside a temporary container
 #---------------------------------------------------------------------
 FROM fedora:32 AS skopeo-build
 
 RUN dnf install -y golang git make
 RUN dnf install -y go-md2man gpgme-devel libassuan-devel btrfs-progs-devel device-mapper-devel
-RUN git clone --depth 1 -b 'v1.4.1' https://github.com/containers/skopeo $GOPATH/src/github.com/containers/skopeo
+RUN git clone --depth 1 -b 'v1.5.1' https://github.com/containers/skopeo $GOPATH/src/github.com/containers/skopeo
 RUN cd $GOPATH/src/github.com/containers/skopeo \
   && make bin/skopeo DISABLE_CGO=1 \
   && make install
 
+#---------------------------------------------------------------------
+# STAGE 2: Build credential helpers inside a temporary container
+#---------------------------------------------------------------------
 FROM golang:1.17 AS cred-helpers-build
 
 RUN go get -u github.com/awslabs/amazon-ecr-credential-helper/ecr-login/cli/docker-credential-ecr-login
 RUN go get -u github.com/chrismellard/docker-credential-acr-env
 
 #---------------------------------------------------------------------
-# STAGE 2: Build the kubernetes-monitor
+# STAGE 3: Build the kubernetes-monitor
 #---------------------------------------------------------------------
 FROM registry.access.redhat.com/ubi8/ubi:8.5