Incorrect previous cloud session is opened after delegation

[bamurtaugh]

After verifying the repo picker appears for cloud sessions on the welcome page (the fix for #290511 by @DonJayamanne), I experienced a separate issue: a previous unrelated different cloud session from 6 months ago was opened in my VS Code after delegation:

The new correct session + PR would've been bamurtaugh/devcontainers.github.io#61 (which was just generated).

I believe we discussed this is due to #289345, but per @DonJayamanne's recommendation, I'm filing an issue just in case we want to track it separately.

[bamurtaugh]

I ran into this again today:

• Empty VS Code Insiders (no repo / workspace open)
• Delegate a task to cloud agent by selecting a repo from the cloud repo picker dropdown
• ❓ A random previous PR is opened in the chat panel
• ❓ Because I'm in an empty workspace and cloud sessions only appear in the agent sessions list if I have that repo open, it seems as though my cloud agent session just disappeared
  • If I go manually open the workspace, I do see the session