[Feature]: Add dependeabot to update actions

[xylar]

How will this affect the next version number?

New feature (increment MINOR version)

Is your feature request related to a problem?

We just added a capability to update pre-commit dependencies. The equivalent for Actions is much easier -- enable dependabot:
https://docs.github.com/en/code-security/how-tos/secure-your-supply-chain/secure-your-dependencies/auto-update-actions

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response

[xylar]

Also see:
https://github.com/E3SM-Project/polaris/blob/main/.github/dependabot.yml