Testing with docker

[furtib]

Why:
We want to expand our environment setup methods for testing.

What:

• Added docker to .ci

Addresses:
#224 and #163

Note:

• An action run of this passing:
  • Normal run on 7.7.0: https://github.com/furtib/rules_codechecker/actions/runs/27073238329
  • To see the cache working (even with a different Bazel version 8.5.0): https://github.com/furtib/rules_codechecker/actions/runs/27073392795/ (the cache essentially halves the runtime)

[Szelethus]

The greatest design element that troubles me is that we are rather committed to using micromamba for testing purposes. Shouldn't we consider integrating it?

[Szelethus]

These could just replace our existing ubuntu/rhel setups, right?

[Szelethus]

The greatest design element that troubles me is that we are rather committed to using micromamba for testing purposes. Shouldn't we consider integrating it?

I understand your reservations about adding this completely. Loosely qouting @nettle, a motivating point of this containerization was to find even more dependencies, and build a minimal but complete, from-scratch image that runs these rules neatly.

On the other hand, I'd viewed the micromamba environment setup as a "single source of truth". Or was it not? Can we at least justify landing multiple (micromamba + one for each supported platform), seemingly competing "single source of truth" setups in the same repo?