Workbench: Add requirements for distrobox.

As described at
https://github.com/89luca89/distrobox/blob/main/docs/posts/distrobox_custom.md.

workbench/Dockerfile

@@ -112,6 +112,7 @@ RUN apt-get update && \
         ostree \
         packer=1.9.4-1 \
         php-cli \
+        pigz \
         plocate \
         postgresql-client \
         protobuf-compiler \
@@ -143,6 +144,7 @@ RUN apt-get update && \
         tmux \
         tnftp \
         transmission-cli/unstable \
+        tree \
         ttyrec \
         udftools \
         unzip \
@@ -153,6 +155,7 @@ RUN apt-get update && \
         w3m-img \
         wget \
         whois \
+        xauth \
         xdg-user-dirs \
         zip \
     && \