Session cleanup in VSphere Cloud Provider

https://github.com/kubernetes/cloud-provider-vsphere

improve Vsphere API session cleanup and reuse in upstream VSphere cloud provider.

good jumping off point for researching this issue: https://github.com/kubernetes/cloud-provider-vsphere/blob/d5f062858935b9c50b0e8e53463b6985ca34494c/pkg/common/vclib/connection.go#L55

Start with pkg/common/vclib/connection.go at the referenced location and trace how VSphere API sessions are created, reused, and cleaned up in the upstream cloud provider. Compare the current behavior with the issue's goal, then define completion as improved session cleanup and reuse without expanding beyond that provider integration.

Written by the indexing model from the issue text.