simplify robotpkg

docker/robotpkg/Dockerfile

 FROM ubuntu:jammy
 
-# Setup Robotpkg apt binary repository
-ADD http://robotpkg.openrobots.org/packages/debian/robotpkg.key /
-RUN --mount=type=cache,sharing=locked,target=/var/cache/apt \
-    --mount=type=cache,sharing=locked,target=/var/lib/apt \
-    apt-get update -y && DEBIAN_FRONTEND=noninteractive apt-get install -qqy --no-install-recommends \
-    gnupg2 \
- && gpg --dearmor /robotpkg.key \
- && mv /robotpkg.key.gpg /usr/share/keyrings/robotpkg.gpg \
- && echo "deb [arch=amd64 signed-by=/usr/share/keyrings/robotpkg.gpg] \
-          http://robotpkg.openrobots.org/packages/debian/pub jammy robotpkg" \
- >> /etc/apt/sources.list.d/robotpkg.list \
- && echo "deb [arch=amd64 signed-by=/usr/share/keyrings/robotpkg.gpg] \
-          http://robotpkg.openrobots.org/wip/packages/debian/pub jammy robotpkg" \
- >> /etc/apt/sources.list.d/robotpkg.list
+ADD http://robotpkg.openrobots.org/packages/debian/robotpkg.asc /etc/apt/keyrings/robotpkg.asc
+RUN echo "deb [arch=amd64 signed-by=/usr/share/keyrings/robotpkg.asc] http://robotpkg.openrobots.org/wip/packages/debian/pub jammy robotpkg" /etc/apt/sources.list.d/robotpkg.list
+RUN echo "deb [arch=amd64 signed-by=/usr/share/keyrings/robotpkg.asc] http://robotpkg.openrobots.org/packages/debian/pub jammy robotpkg" /etc/apt/sources.list.d/robotpkg.list