feat: allow changing the Docker runtime

[rickstaa]

What does this pull request do? Explain your changes. (required)

The previous implementation used the default Docker runtime. This change adds support for specifying a different runtime—for example, kata—to improve container isolation.

Specific updates (required)

How did you test each of these updates (required)

Does this pull request close any open issues?

Checklist:

• [ ] Read the contribution guide
• [ ] make runs successfully
• [ ] All tests in ./test.sh pass
• [ ] README and other documentation updated
• [ ] Pending changelog updated