Bayesloop

Fixes deprecated use of `np.float`, `np.int`, etc.

Switch from `dill` to `cloudpickle` for saving/loading `Study`-objects to/from file. This ensures compatibility with JupyterLite as `dill` cannot easily be imported in a `pyodide` kernel.

Fix deprecated import from `collections` to ensure compatibility with Python 3.10.

- Fix saving/loading models
- Fix initialization of backwards pass
- Fix tests

Re-release because of broken wheel file.

Re-release due to pypi version conflicts.