Allow auto merge to Dependabot PR if they pass CI

[HarelM]

Enable auto merge to dependent bot if CI passes.

Heavily relies on https://rednafi.github.io/reflections/automerge-dependabot-prs-on-github.html

I've been spending a lot of time simply clicking approve on dependant bot PRs.
I hope this will reduce the time I need to spend on this.

@birkskyum @zhangyiatmicrosoft

[wipfli]

@stepankuzmin has something like that for Martin. Feel free to copy from there

[HarelM]

Thanks for the info! I see that they have automatic approve there as well, I'll add that too.

[stepankuzmin]

https://github.com/maplibre/martin/blob/main/.github/workflows/dependabot.yml

[HarelM]

Thanks @stepankuzmin! I've updated the action according to the example in martin.

[birkskyum]

It's a good idea, but it has to run tests for each commit - had issues in the past that it merged a ton of commits at once, some of which were incompatible, so each commit has to invalidate the existing checks. Having dependabot only open one ticket at a time could be a reasonable way to enforce it and at the same time avoid spending time making checks that would later be invalidated.

[HarelM]

I think it will run the tests as far as I read.

[HarelM]

Let's see how it works, worst case we remove this...

[wipfli]

The dependabot open pull request limit is at 20 I think currently. If you get too many incompatibility conflicts, you might want to turn this number down again...