ci: add weekly Jenkins mini-e2e job against ceph main

[Coderxrohan]

Describe what this PR does

1. This PR adds a weekly Jenkins-based mini E2E job that runs against the Ceph main branch.
2. The job is implemented under the ci/centos branch using existing Jenkins infrastructure and mini-e2e pipelines. It reuses current scripts and test logic, only introducing a new scheduled job and configuring it to deploy Ceph main for early regression detection.

Provide any external context for the change, if any.

• This follows the goal of catching compatibility issues early when upstream Ceph main introduces changes that may affect ceph-csi behavior, without impacting day-to-day development workflows.

Related issues

• Fixes: Run E2E tests against ceph main branch #5855

Future concerns

If the job proves stable and valuable, it could later be extended to full E2E coverage or enhanced with additional reporting/alerting.

Checklist:

• Commit Message Formatting: Commit titles and messages follow guidelines in the developer guide.
• Reviewed the developer guide on Submitting a Pull Request
• Pending release notes updated with breaking and/or notable changes for the next major release (not required for CI-only change).
• Documentation has been updated, if necessary (not required).
• Unit tests have been added, if necessary (not applicable).
• Integration tests have been added, if necessary (existing mini E2E reused)

[Madhu-1]

IMHO, this is not very helpful as we will know whether this job ran successfully or not, we need to write a github action that will run every sunday/monday that will update the ceph version and image and create a PR, we need to further need to add the required labels to start CI jobs

I like this idea because we will get to know there is a PR and we need to monitor it, weekly jobs goes unnotice easly.

@nixpanic @Rakshith-R thoughts?

[Coderxrohan]

Agree! A scheduled GH action that creates a PR with labels feels more effective.
Happy to help design this if aligned.
@nixpanic @Rakshith-R