Remove Humble and Iron from tutorial Docker CI job

[sea-bass]

Description

These jobs have been failing as optional for a while, and the main branch of moveit2 just will not work with these older tutorial versions. So I opt for removing them here.

If anything, the tutorial job should be added into the humble branch to test that specific pipeline -- doing in #3082.

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

[rr-tom-noble]

Thanks for doing this! Those failing workflows have been irking me in recent PRs 😅

Happy to close #3078 with this

[rhaschke]

If you don't plan to make them working, these should be removed here. I agree.

[sea-bass]

If you don't plan to make them working, these should be removed here. I agree.

I am moving the job for Humble to the humble branch in #3082

As for Iron? The tutorials haven't really worked on that version for a while (there isn't even an iron branch in the moveit2_tutorials repo), and it's been so long that Iron is almost EOL. 😢