Downgrade Devcontainer to Debian Bullseye and Preinstall Playwright Dependencies

[Eclipse-Dominator]

Fixes #1346

Description:
This PR addresses the issue of Playwright not being supported in our current devcontainer, which uses Debian Bookworm. To resolve this, we are:

1. Downgrading the devcontainer base image from Debian Bookworm to Debian Bullseye, which is supported by Playwright.
2. Preinstalling Playwright's browser dependencies to ensure seamless setup for development and testing workflows.

Changes Included:

• Updated base image to use debian:bullseye.
• Added necessary commands to preinstall Playwright's browser dependencies.

Why This Change is Necessary:
Playwright is a critical tool for end-to-end testing in our project, and the lack of support in the current devcontainer is blocking development and testing efforts. This change ensures compatibility and a smoother developer experience.

Proposed Commit message

Preinstall Playwright Dependencies in devcontainer

Playwright dependencies is currently not readily supported in Debian
bookworm which is used by the devcontainer.

As CATcher uses Playwright to do e2e testing, let's
- downgrade the devcontainer to Debian bullseye to support Playwright
- Preinstalls the Playwright testing browser dependencies in the
  container

[Arif-Khalid]

LGTM!