Xarray-ome-ngff

v2.1.0 broke python 3.9 compatibility, due to over zealous use if the `|` operator for expressing union types. This release removes the broken type definitions, and restores python 3.9 compatibility.

**Full Changelog**: https://github.com/JaneliaSciComp/xarray-ome-ngff/compare/v2.1.0...v2.1.1

- Generally improves type annotations
- Renamed `fuse_coordinate_transforms` to `normalize_transforms`, and simplified its usage
- `model_group` and `create_group` now take chunks, compressor, and fill value kwargs.
- DataArray coordinates must now have consistent dims and units when creating multiscale metadata

**Full Changelog**: https://github.com/JaneliaSciComp/xarray-ome-ngff/compare/v2.0.0...v2.1.0

What's Changed
* add github actions by d-v-b in https://github.com/JaneliaSciComp/xarray-ome-ngff/pull/4
* wild overhaul by d-v-b in https://github.com/JaneliaSciComp/xarray-ome-ngff/pull/3


**Full Changelog**: https://github.com/JaneliaSciComp/xarray-ome-ngff/compare/v1.2.3...v2.0.0