Adapt Che-Code to work with Dev Spaces Copilot Chat Integration

[RomanNikitenko]

Is your task related to a problem? Please describe

I tested Dev Spaces Copilot Chat Integration installation in the che-code.
It does not work, the error is:

An error occurred while setting up chat. Would you like to try again?
The extension 'GitHub.copilot-chat' cannot be installed because it was not found.

Describe the solution you'd like

I think some adaptation is required on the Che-Code side to work with the Dev Spaces Copilot Chat Integration

Describe alternatives you've considered

No response

Additional context

No response

[RomanNikitenko]

Done in che-incubator/che-code#646:

• Configure defaultChatAgent for devspaces-copilot-chat-integration: che-incubator/che-code@199009d
• Rebase rules: che-incubator/che-code@eb92105