Reset or remove dependabot (and corresponding PRs)

[jblehr]

We have a bunch of open "depandabot" PRs that appear to be outdated (with the last one in June 2024).

If we are going to use depandabot (because it's a useful/necessary service), then we should probably create a plan to merge in some of these and close the rest. Or close all of these, re-start the bot, and merge any new PRs.

If not, then I think they should be closed and the bot should be deactivated.

@davidye007 - I'm not exactly sure how this works, but it'd sure be nice to not have all of these open PRs hanging out in this repo. What do you think we should do?