renovate: Add renovate and pipeline changes

Commit Message Prefix: "commitMessagePrefix": "renovate:"
ensures that all Renovate-generated commits use the specified prefix.
Grouping Dependencies: The "group" configuration
consolidates all Python dependency updates into a single MR.
Dependency Dashboard: Enabled with "dependencyDashboard": true
to give an overview of all dependency updates.
PR Rate Limits: Limits PR creation to 2 per hour and a maximum of 5
open PRs concurrently, reducing MR noise.