Upgrade VAST Block CSI Driver

Complete these steps to upgrade VAST Block CSI Driver:

Refresh Helm repository information to see which VAST Block CSI Driver versions are available for deployment:
```
helm repo update
```
Update the VAST Block CSI Driver's Helm chart configuration file (values.yaml) to specify the target release of the driver:
```
image:
  csiVastPlugin:
    repository: <repo>
    tag: <new release>
    imagePullPolicy: IfNotPresent
```
Where:
- <repo> is the name of the Helm repository.
- <new release> is the driver release to be upgraded to.
For example:
```
image:
  csiVastPlugin:
    repository: vastdataorg/csi
    tag: v2.6.1
    imagePullPolicy: IfNotPresent
```
Run Helm upgrade:
```
helm upgrade <old release> <repo>/vastblock -f <filename>.yaml
```
Where:
- <old release> is the driver release to be upgraded from.
- <repo> is the name of the Helm repository.
- vastblock is the name of the driver's Helm chart.
- <filename>.yaml is the Helm chart configuration file.
Verify the status of the new release:
```
helm ls
```