Dockerfile: update registry to v3.0.0

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

Dockerfile

@@ -5,7 +5,7 @@ ARG CONTAINERD_VERSION=v2.2.5
 # CONTAINERD_ALT_VERSION_... defines fallback containerd version for integration tests
 ARG CONTAINERD_ALT_VERSION_21=v2.1.9
 ARG CONTAINERD_ALT_VERSION_17=v1.7.33
-ARG REGISTRY_VERSION=v2.8.3
+ARG REGISTRY_VERSION=v3.0.0
 ARG ROOTLESSKIT_VERSION=v3.0.1
 ARG CNI_VERSION=v1.9.1
 ARG STARGZ_SNAPSHOTTER_VERSION=v0.18.2
@@ -300,12 +300,9 @@ ARG TARGETPLATFORM
 RUN --mount=target=/root/.cache,type=cache <<EOT
   set -ex
   mkdir /out
-  export GOPATH="$(pwd)/Godeps/_workspace:$GOPATH"
-  GO111MODULE=off CGO_ENABLED=0 xx-go build -o /out/registry ./cmd/registry
-  xx-verify --static /out/registry
-  if [ "$(xx-info os)" = "windows" ]; then
-    mv /out/registry /out/registry.exe
-  fi
+  ext=$(xx-go env GOEXE)
+  CGO_ENABLED=0 xx-go build -o "/out/registry${ext}" ./cmd/registry
+  xx-verify --static "/out/registry${ext}"
 EOT
 
 FROM gobuild-base AS rootlesskit