[cleanup]: remove deprecated liveness driver and related metrics artifacts

[Coderxrohan]

Issue:
Ceph-CSI includes a legacy liveness driver and related deployment artifacts (sidecar containers, Services, ServiceMonitors, and documentation) that are no longer needed. Kubernetes now provides native liveness and health probing, making the custom liveness driver redundant.

Fix:

1. Removed all references to the deprecated liveness driver across the repository:
2. Deleted liveness sidecar containers from RBD, CephFS, and NFS manifests
3. Removed liveness-related Services and ServiceMonitors
4. Cleaned up documentation sections describing liveness metrics and endpoints
5. Ensured generated YAMLs no longer expose unused metrics ports

Impact:

• Simplifies CSI deployments by relying on Kubernetes-native health checks
• Avoids exposing unused ports and services
• Reduces maintenance burden and configuration complexity
• Aligns Ceph-CSI with current Kubernetes best practices

Level:
Medium-severity cleanup / technical debt reduction

Fixes: #5599

[Madhu-1]

@Coderxrohan Thanks for the work, did you get a chance to verify that profing endpoint works if we remove it? what about the code in the liveness.go?

[Madhu-1]

This is kind of a breaking change, we need to add it to Pending release notes. cc @Rakshith-R @nixpanic