Replace gh releases with plain cURL.

The GitHub CLI requires authentication (even though listing releases
doesn't require authentication). Fallback to to using cURL.

Dockerfile

@@ -24,7 +24,7 @@ COPY --chown=root:root sources.d/* /etc/apt/sources.list.d/
 COPY --chown=root:root preferences.d/* /etc/apt/preferences.d/
 # hadolint ignore=DL3008,DL3013,DL3027,DL4001
 RUN apt-get update && \
-    curl --location --silent --fail https://github.com/kubernetes/kompose/releases/download/v1.26.1/kompose_1.26.1_amd64.deb --output /tmp/kompose.deb && \
+    curl --location --silent --fail --show-error https://github.com/kubernetes/kompose/releases/download/v1.26.1/kompose_1.26.1_amd64.deb --output /tmp/kompose.deb && \
     DEBIAN_FRONTEND=noninteractive apt-get install --yes --no-install-recommends \
         adb \
         apache2-utils \
@@ -241,10 +241,10 @@ RUN apt-get update && \
     chmod +x /usr/local/bin/rabbitmqadmin && \
     mkdir /usr/local/share/bfg && \
     wget 'https://search.maven.org/remote_content?g=com.madgag&a=bfg&v=LATEST' -qO /usr/local/share/bfg/bfg.jar && \
-    gh release download --repo genuinetools/reg --pattern "reg-$(go env GOOS)-$(go env GOARCH)" && \
-    install -o root -g root -m 0755 /usr/local/bin/reg reg-* && \
-    gh release download --repo rancher/rke --pattern "rke_$(go envGOOS)-$(go env GOARCH)" && \
-    install -o root -g root -m 0755 /usr/local/bin/rke rke_* && \
+    curl --silent --location --fail --show-error "https://github.com/genuinetools/reg/releases/download/v0.16.1/reg-$(go env GOOS)-$(go env GOARCH)" --output /tmp/reg && \
+    install -o root -g root -m 0755 /usr/local/bin/reg /tmp/reg && \
+    curl --silent --location --fail --show-error "https://github.com/rancher/rke/releases/download/v1.3.8/rke_$(go env GOOS)-$(go env GOARCH)" --output /tmp/rke && \
+    install -o root -g root -m 0755 /usr/local/bin/rke /tmp/rke && \
     _PIPENV_COMPLETE=bash_source pipenv > /etc/bash_completion.d/pipenv && \
     rabbitmqadmin --bash-completion  > /etc/bash_completion.d/rabbitmqadmin && \
     poetry completions bash > /etc/bash_completion.d/poetry && \