Downgrade Devcontainer from Debian Bookworm to Bullseye for Playwright Support

[Eclipse-Dominator]

Description:
Our current devcontainer uses Debian Bookworm, which is not supported by Playwright. As a result, installing Playwright dependencies is not possible in the current devcontainer image. This issue proposes downgrading the devcontainer from Debian Bookworm to Debian Bullseye and preinstalling Playwright's browser dependencies since CATcher uses Playwright to perform e2e testing.

Steps to Reproduce:

1. Use the current devcontainer.
2. Attempt to install Playwright dependencies.
3. Observe that the installation fails due to unsupported dependencies.

Expected Behavior:
Playwright dependencies should install successfully, and the devcontainer should support Playwright's browser automation tools.

Proposed Solution:

• Downgrade the devcontainer base image from Debian Bookworm to Debian Bullseye.
• Preinstall Playwright's browser dependencies in the devcontainer.

Additional Context:
Playwright is a critical tool for end-to-end testing in our workflow, and its lack of support in the current devcontainer is blocking development and testing efforts.