Include xorriso

Dockerfile

@@ -32,7 +32,6 @@ RUN dpkg -i /tmp/packages-microsoft-prod.deb && \
       build-essential \
       curl \
       git \
-#      gnupg \
       jq \
       # (locales) Dependency for InSpec
       locales \
@@ -43,6 +42,8 @@ RUN dpkg -i /tmp/packages-microsoft-prod.deb && \
       python3-pip \
       python3-setuptools \
       python3-wheel \
+      # (xorriso) Dependency for Packer (generating isofs image)
+      xorriso \
       yamllint && \
     sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && \
     locale-gen && \