Echo

<!-- Release notes generated using configuration in .github/release.yml at main -->
What's Changed

Bug Fixes

- Added test for connect_list_selection and fix remaining PyQt6 issue by astrofrog in https://github.com/glue-viz/echo/pull/35

**Full Changelog**: https://github.com/glue-viz/echo/compare/v0.7...v0.8.0

What's Changed

Bug Fixes

- Fix compatibility with PyQt6 by astrofrog in https://github.com/glue-viz/echo/pull/29

Other Changes

- Migrate CI tests and publishing task to GitHub Actions by dhomeier in https://github.com/glue-viz/echo/pull/33
- Add PySide6 test envs to CI by dhomeier in https://github.com/glue-viz/echo/pull/34

New Contributors

- dhomeier made their first contribution in https://github.com/glue-viz/echo/pull/33

**Full Changelog**: https://github.com/glue-viz/echo/compare/v0.5...v0.6

- Fixed compatibility with recent PyQt5 versions.

- Add the ability to specify for `SelectionCallbackProperty` whether to
- compare choices using equality or identity. [26]
-
- Fixed an issue that could lead to `CallbackContainer` returning dead
- weak references during iteration. [27]
-

- Added the ability to add arbitrary callbacks to `CallbackDict` and
- `CallbackList` via the `.callbacks` attribute. [25]

- Fix setting of defaults in callback list and dict properties. [24]