Support for container runtime + bump to Node.js 25

[ViMaSter]

Stumbled across your call for participation in the VOC IRC. Looks awesome!

I've managed to get this running on my hardware, just did a bit of housekeeping, you might be interested in:

• 30faf90: Node.js 20 is out of support already. I've bumped the project to Node.js 25
  • Also changed the CI to always run on 25 and the latest version of Node.js
  • If Node.js releases a new major version, this CI build will partially fail, raising awareness that CCCBIB requires changes to work with the newest version of Node.js
  • Stability of the Docker image remains though, as it always runs with the pinned version of Node.js (25 for now)
• f9a9281 adds a third pipeline, which just builds a Docker image that contains a working version of CCCBIB exposed at port 80 and pushes it to the GitHub container registry
  • Using that image I'm hosting https://cccbib.by.vincent.mahn.ke; the compose file used for it can be found at https://github.com/mahn-ke/cccbib-by-vincent/blob/main/docker-compose.yml

If you're interested, I can kick off a discussion at my local hackerspace about hosting this on CCC hardware; that would make it possible to host this under a ccc.de domain.

Also available via Matrix or Discord if you prefer a quick chat or call about this; details are on my website. Or feel free to disregard this PR altogether. :)

[volkovmqx]

Amazing! Thank you for the clean up ^^
Hosting this under ccc.de would be amazing, maybe something short and snackable, so people can write that themselves in their TVs browser.