Documentation
* docs(changelog): update changelog ([`a6a32a0`](https://github.com/xarray-contrib/xeofs/commit/a6a32a0b94c7ddd82d028c89321c0a0d3e5c61b2))
Fixes
* fix: isolate required and optional dependencies (237)
Allow more minimal installs by making certain packages optional, namely the backend engines (`h5netcdf, `netcdf4`, and `zarr`) used for saving and loading models, plus `statsmodels` which is used for CPCCA-derived models, and `numba` which is used for GWPCA. ([`a6c05e6`](https://github.com/xarray-contrib/xeofs/commit/a6c05e6117e989da23c18b66d0a908f88860e117))