helm diff job fails with helm 4
## Describe the bug
The `helm-diff-xxx` jobs do not work with Helm 4.
## Expected behavior
The `helm-diff-xxx` jobs should work with both Helm 3 and Helm 4.
## Actual behavior
```bash
level=WARN msg="command failed" error="invalid color mode \"xxx\": must be one of: never, auto, always"
```
Seems to be related to [this](https://github.com/databus23/helm-diff/issues/880) bug.
The recommendation is to set the `HELM_DIFF_COLOR` variable instead of the `--color` parameter
issue