clean-up: add dependabot

[perdasilva]

Description of the change:
Adds dependabot configuration to .github that will submit update PRs on a weekly basis to update go mod dependencies as well as github actions

Motivation for the change:

Architectural changes:

Testing remarks:

Reviewer Checklist

• Implementation matches the proposed design, or proposal is updated to match implementation
• Sufficient unit test coverage
• Sufficient end-to-end test coverage
• Bug fixes are accompanied by regression test(s)
• e2e tests and flake fixes are accompanied evidence of flake testing, e.g. executing the test 100(0) times
• tech debt/todo is accompanied by issue link(s) in comments in the surrounding code
• Tests are comprehensible, e.g. Ginkgo DSL is being used appropriately
• Docs updated or added to /doc
• Commit messages sensible and descriptive
• Tests marked as [FLAKE] are truly flaky and have an issue
• Code is properly formatted

[tmshort]

I thought we already had this? e.g.
#3205
Is this just configuration?

[itroyano]

That's a bit confusing @tmshort because I don't see a dependabot.yml in this repo. I see it in OLM v1 repo though.

[perdasilva]

I think only security updates are enabled. I figured it would be good to have a configuration file anyway to keep it all as code.

[tmshort]

/lgtm
/approve