… from source (#2818) * fix(snap): install python3-apt as a stage-package instead of building from source uv now rejects source distributions with non-PEP 625-compliant filenames (e.g. python-apt's .tar.xz release from Launchpad), which broke the snap build. Since the snap can't use the prebuilt python-apt wheels (they're built for a different environment), install python3-apt as a distro stage-package in the charmcraft-libs part instead, and organize its files into the charmcraft venv's site-packages. * fix(tests): resolve ruff lint failures in test suite Fix 4 ruff errors from the lint job: - PLR0917 (too many positional args) in tests/conftest.py and tests/unit/commands/test_store.py fixtures/tests, resolved by marking excess parameters as keyword-only since pytest injects fixtures by name. - ISC004 (unparenthesized implicit string concatenation in a list) in tests/unit/parts/plugins/test_charm.py and test_reactive.py, resolved by wrapping the concatenated string in parentheses. * refactor(snap): move python3-apt to its own part, matching snapcraft's approach Mirrors canonical/snapcraft#5872: split python3-apt into a dedicated nil-plugin part with a single glob organize rule, rather than stacking it onto charmcraft-libs with per-file organize entries. --------- Describe your changes. --- - [ ] I've followed the [contribution guidelines](https://github.com/canonical/charmcraft/blob/main/CONTRIBUTING.md). - [ ] I've signed the [CLA](http://www.ubuntu.com/legal/contributors/). - [ ] I've successfully run `make lint && make test`. - [ ] I've added or updated any relevant documentation. - [ ] In documents I changed, I [added a meta description](https://canonical-starflow.readthedocs-hosted.com/how-to/add-a-page-meta-description/) if one was missing. - [ ] I've updated the relevant release notes.