[INFRA]: Reset GHA workflow ownership

### Is this a duplicate?

- [x] I confirmed there appear to be no [duplicate issues](https://github.com/NVIDIA/cccl/issues) for this request and that I agree to the [Code of Conduct](CODE_OF_CONDUCT.md)

### Overview

I'm still the owner of the CCCL nightly + weekly workflows:

- https://github.com/NVIDIA/cccl/blob/main/.github/workflows/ci-workflow-nightly.yml
- https://github.com/NVIDIA/cccl/blob/main/.github/workflows/ci-workflow-weekly.yml

Apparently github picks the owner of scheduled runs based on whoever was the last to (a) edit the `schedule` line of the workflow yaml, or (b) disable/enable the workflow: https://docs.github.com/en/actions/concepts/workflows-and-actions/notifications-for-workflow-runs

It's a small annoyance (I get email spam about failures, not sure what else comes with this 'ownership'), at some point someone else should take this role.

### Details

This issue can be closed by making a trivial edit to the `schedule:` lines of the above linked workflows.

Open .github/workflows/ci-workflow-nightly.yml and .github/workflows/ci-workflow-weekly.yml and inspect their schedule: lines. Make a trivial edit to those lines so scheduled workflow ownership transfers to the contributor, then confirm both workflow files contain the intended schedule configuration.

Written by the indexing model from the issue text.