[fix][build] Switch to Bookworm image after Bullseye reached EOL - #506

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v3, actions/setup-node@v3, actions/setup-python@v3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

'topicMetadata' is defined but never used

'message' is defined but never used

'messageConsumer' is defined but never used

'message' is defined but never used

'messageConsumer' is defined but never used

'message' is defined but never used

Test has no assertions

'reader' is defined but never used

'message' is defined but never used