Fills out the core26 spread test suite. In order to make this possible to review, the table below describes the level of scrutiny for each commit: | commit number | commit | notes | | ---- |-------|-------| | 1 | ci: add job for core26 spread tests | this adds a new CI job for the core26 suite | | 2 | test(spread): remove dangling symlink | unrelated cleanup, the dangling symlink wasn't being used | | 3 | test(spread): copy tests to common dir | - copy/paste of `core24/` and `core24-suites/` to `_common/`. <br> - flattens nested directories in the `core24-suites` <br> - moves the `python-hello` <br> This commit isn't very useful to review. | | 4 | test(spread): reorder task.yaml keys | A long overdue refactor to improve readability. <br> All task.yaml keys in `_common/` are now ordered chronologically: prepare -> execute -> restore. <br> This is programmatic and not very useful to review. | | 5 | test(spread): set and restore bases | In order to generalize the common tests, the `base` entry in each `snapcraft.yaml` need to be set during `prepare` and reverted during `restore`. So this adds `set_base` and `restore_yaml` to every test that was missing it. <br> Again, this is programmatic and not very useful to review. | | 6 | test(spread): symlink common tests for core26 | Another programmatic commit that creates symlinks in the core26 directory | | 7 | test(spread): generalize spread tests | This is where the proper hands-on work was done. My goal was to make the tests pass on core26 or have them fail with an expected error and link them to a github issue. <br> I did a best effort attempt to make them generic enough to be used for core22, core24, and core28(!), although minor changes will certainly be needed. | (SNAPCRAFT-1328) --- - [x] I've followed the [contribution guidelines](https://github.com/canonical/snapcraft/blob/main/CONTRIBUTING.md). - [x] I've signed the [CLA](http://www.ubuntu.com/legal/contributors/). - [x] I've successfully run `make lint && make test`. - [ ] I've added or updated any relevant documentation. - [ ] I've updated the relevant release notes.