chore(dependabot): add project config

[MichaelDoyle]

Reduce noise by grouping PRs into high leve groups on a weekly schedule.

We talked about trying to do something like this a while back. I'm on "rotation" this week -- so finally getting around to it.

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs updated (updated docs or a docs bug required)

[gemini-code-assist]

Code Review

This pull request introduces a .github/dependabot.yml configuration to automate dependency updates for GitHub Actions, npm, Go, and Python. Feedback indicates several potential issues with the current setup: the Python ecosystem's use of uv is not natively supported by Dependabot's pip provider; the npm configurations may encounter issues with pnpm 10 and pnpm.overrides; and the Go configuration references an unstable version (1.25.0) which may cause parsing failures.