Backport 2 :arrow_left: 5 - Add standalone executables (#121)

[Crola1702]

🦟 Bug fix

Fixes #208

Summary

Suggested by https://github.com/gazebosim/gz-launch/issues/208#issuecomment-2070534677 to check if this fixes the problem

Checklist

• [X] Signed all commits for DCO
• [ ] Added tests
• [ ] Updated documentation (as needed)
• [ ] Updated migration guide (as needed)
• [ ] Consider updating Python bindings (if the library has them)
• [ ] codecheck passed (See contributing)
• [ ] All tests passed (See test coverage)
• [ ] While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[claraberendsen]

@Crola1702 could you rebase and force push with lease with a signed commit? That way the DCO bot won't complain.