Install Gazebo in tutorial image Dockerfile

[sea-bass]

Description

This is the equivalent of moveit/moveit2_tutorials#937, but for this repo. Should hopefully make CI green.

Checklist

• Required by CI: Code is auto formatted using clang-format
• Extend the tutorials / documentation reference
• Document API changes relevant to the user in the MIGRATION.md notes
• Create tests, which fail without this PR reference
• Include a screenshot if changing a GUI
• While waiting for someone to review your request, please help review another open pull request to support the maintainers

[sea-bass]

Hmm... seems like the gz_plugin_vendor package is only available on Jazzy and Rolling, so it's only going to fix it for that.

To support humble/iron, we'll need to pull in different versions of the ros2_kortex repo, that don't transitively depend on the gz_ros2_control package.

[sjahr]

Thanks for digging into this! Fixing at least jazzy and rolling is a big step forward 🎉