Confusing "Image is not used" warning

### Expected behavior
When there is an error substituting image configuration Skaffold will provide useful information about what went wrong.

### Actual behavior
Only the following information is provided regarding the problem, even after enabling trace level logging
```log
WARN[0003] image [docker.server.com:5000/my-service:519e2dec4d1729496236eec9f3ccae7cefb7f5da1dc3fcf79f54e0935f82f761] is not used. subtask=-1 task=DevLoop
WARN[0003] See helm documentation on how to replace image names with their actual tags: https://skaffold.dev/docs/pipeline-stages/deployers/helm/#image-configuration subtask=-1 task=DevLoop
```

While the document is comprehensive, it also explains multiple cases influenced by a number of external parameters. It's quite hard to guess the correct configuration without getting any constructive feedback on the error.

From my observations switching from `chartPath` to `remoteChart` can also lead to this error although it is not mentioned in the documentation.

### Information

- Skaffold version: 2.12.0
- Operating system: Ubuntu 22.04.4
- Installed via: curl -Lo skaffold https://storage.googleapis.com/skaffold/releases/latest/skaffold-linux-amd64 && \ sudo install skaffold /usr/local/bin/