disable dependabot?

[yarikoptic]

We have requirements.txt for various notebooks.

• dependabot sends multitude PRs: https://github.com/dandi/example-notebooks/pulls?q=is%3Apr+dependabot+
• @bendichter merged some, some remain open
• there is no guarantee that notebooks would work with more recent versions of dependencies
• there is no guarantee that results would be reproducible with newer versions
• there is no guarantee that new upgraded versions would be coinstallable and compatible with older versions of the others

with that in mind, I think we should just disable dependabot for this repo and close all those PRs unmerged

If there is no feedback/counter arguments, I will do that in a week

[bendichter]

Yes, I think that's fine. I thought it would be a quick thing but the PRs keep on coming