Use same renovate configuration as dotnet-sdk

[askpt]

Description

Renovate was reopening PR #438, which appears to be marked as "immortal." This behaviour suggests that there might be a configuration issue in our Renovate setup.
One of the suggestions is to set the updates to be open only on approval: https://docs.renovatebot.com/key-concepts/pull-requests/#immortal-prs.

Tasks

1. Copy the renovate configuration from dotnet-sdk.

Notes

See open-feature/dotnet-sdk#448