chore: update github actions with dependabot [SYNTH-149]

[0xda157]

Task

SYNTH-149

Symptom

Github Actions uses pins aren't automatically updated, which is a security risk.

Solution

Add automated updating via Dependabot

Warning

This PR requires enabling Dependabot in settings to function.

Verification

---

Before merging, ensure the following criteria are met:

• All acceptance criteria outlined in the ticket are met.
• Necessary test cases have been added and updated.
• A feature toggle or safe disable path has been added (if applicable).
• User-facing polish:
  • Ask: "Is this ready-looking?"
• Cross-linking between Jira and GitHub:
  • PR links to the relevant Jira issue.
  • Jira ticket has a comment referencing this PR.

[PepperLola]

I support this as long as it isn't too annoying or intrusive during the periods of inactive development we have each year. It sounds like it'll automatically update/close its old PRs which seems fine

[AlexD717]

Config looks good to me

[0xda157]

I support this as long as it isn't too annoying or intrusive during the periods of inactive development we have each year. It sounds like it'll automatically update/close its old PRs which seems fine

It'll just keep updating the PRs to latest version until they get merged or closed, so I don't think it'll be too big of an annoyance over the summer.