Support Ubuntu 26.04 LTS ("Resolute Raccoon") in CLI

### Preconditions

- [x] No need to upgrade Python SDK or the Python SDK is ready.

### Related command

Ubuntu 26.04 LTS ("Resolute Raccoon") was officially released on April 23, 2026 and is expected to see broad adoption as the latest long-term support version. To ensure compatibility and maintain a smooth user experience, we propose adding official support for Ubuntu 26.04 to the CLI, including validation of core functionality, installation flows, and dependency compatibility on this platform. This work should also include updating CI/CD pipelines to test against Ubuntu 26.04 and refreshing documentation accordingly. Without this support, users upgrading from previous LTS versions may encounter compatibility issues or degraded reliability.

### Resource Provider

https://releases.ubuntu.com/resolute/

### Description of Feature or Work Requested

Ubuntu 26.04 LTS ("Resolute Raccoon") was officially released on April 23, 2026 and is expected to see broad adoption as the latest long-term support version. To ensure compatibility and maintain a smooth user experience, we propose adding official support for Ubuntu 26.04 to the CLI, including validation of core functionality, installation flows, and dependency compatibility on this platform. This work should also include updating CI/CD pipelines to test against Ubuntu 26.04 and refreshing documentation accordingly. Without this support, users upgrading from previous LTS versions may encounter compatibility issues or degraded reliability.

### Minimum API Version Required

https://releases.ubuntu.com/resolute/

### Swagger PR link / SDK link

https://releases.ubuntu.com/resolute/

### Request Example

https://releases.ubuntu.com/resolute/

### Target Date

2026

### PM Contact

Alex wang

### Engineer Contact

Nga

### Additional context

_No response_