[code] integration test cut-through

[akosyakov]

It would be good to automate testing of Code integration.

Tasks

• provide nightly version: Add code nightly option in dashboard #6094
• enable nightly werft job: https://github.com/gitpod-io/gitpod/issues/6200
• deploy nightly version
• allow to run VS Code test extension against Gitpod Code server running in the workspace
• configure running nightly integration tests against stable
• setup slack notifications for nightly version build as well as nightly integration tests

[csweichel]

Ideally integrated into our integration tests, so that the Code integration tests would be part of Gitpod's integration tests.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[akosyakov]

We do really a lot of repetitive testing each month. It is better to look into how it can be automated.