[MISC] Update the active maintainer section and move in-active maintainers t…

[randombet]

…o the past maintainers

Why are these changes needed?

Update the maintainers list.

Related issue number

Checks

• [ ] I've included any doc changes needed for https://docs.ag2.ai/. See https://docs.ag2.ai/latest/docs/contributor-guide/documentation/ to build and test documentation locally.
• [ ] I've added tests (if relevant) corresponding to the changes introduced in this PR.
• [ ] I've made sure all auto checks have passed.

[joggrbot[bot]]

Joggr analysis skipped - Only markdown files were changed

[randombet]

Need to update https://docs.ag2.ai/latest/docs/contributor-guide/maintainer/ as well.

[elCaptnCode]

@randombet can you add me or what are your thoughts?

[elCaptnCode]

You should add me