Addressed some MR comments.

This should allow full Python functionality without building wheels.

[ci] Fix guix pack

See merge request ogs/ogs!4879

[py] Ruff fixes

See merge request ogs/ogs!4866

Hm subdomain deactivation fix

Closes #3372

See merge request ogs/ogs!4865

[LIE/HM] Improve output

See merge request ogs/ogs!4851

Small optimization for first variable, no need to make a set_union
with empty _ids_of_active_elements.

Revert "[py] ruff fixes in Tests/Data/ThermoHydroMechanics/Linear/Point_injection/SaturatedPointheatsource.ipynb."

This reverts commit 138138b4.

Pickle fix is required on all platforms but breaks subsequent code in
e.g.

    print(result[0])
    runtimes.append(result[1])

[py] ruff fixes in Tests/Data/Mechanics/InitialStates/soil_column_nonequilibrium_sigma_generate_values.py.