Support Python 3.12 and AiiDA 2.8

[cpignedoli]

Summary

• Require Python 3.12 and AiiDA 2.8.
• Use the AiiDA-2.8-native Vibroscopy/Phonopy backend line and Euphonic 1.4.5.
• Remove the unused direct aiida-pythonjob dependency; it remains transitive through aiida-phonopy.
• Validate the supported runtime during CI installation.

Validation

Tested in a local AiiDAlab instance with Python 3.12.11, AiiDA 2.8.0, AiiDAlab 26.5.2, aiidalab-qe 26.4.0, aiida-vibroscopy 1.6.0, aiida-phonopy 1.7.0, Phonopy 3.5.1, Euphonic 1.4.5.2, and aiida-pythonjob 0.5.2.

pip check, CI, and pre-commit pass. A complete silicon Vibroscopy workflow finished successfully, including dielectric critical-field estimation, finite-field SCFs, numerical derivatives, phonons, and final Phonopy calculations.

The legacy pytest harness still imports host classes removed from current aiidalab-qe (App and ConfigureQeAppWorkChainStep); this is independent of the dependency update.

Dependency

This PR remains draft pending the small backend correction in aiida-vibroscopy#115 and a usable release.

@AndresOrtegaGuerrero @edan-bainglass, please have a look when convenient.

Prepared with Codex assistance.

[cpignedoli]

@AndresOrtegaGuerrero @edan-bainglass: the Python 3.12/AiiDA 2.8 update has now passed the complete dielectric branch in a local AiiDAlab calculation. The PR is linked to the small upstream runtime fix in bastonero/aiida-vibroscopy#115 and will remain draft until that dependency is available.

[cpignedoli]

Update: the same local silicon workflow has now completed fully with exit status 0, including both the dielectric and phonon branches and the final Phonopy calculations.

[AndresOrtegaGuerrero]

LGTM!