Error due to the deprecated xr.open_rasterio() method

Hi,

It looks like intake-stac is affected by the [recent deprecation](https://docs.xarray.dev/en/stable/whats-new.html#id226) of `xarray.open_rasterio()` and throws errors while loading geotiff/COG files.

Here's a minimum reproducible example:
```
import intake

catalog_url = 'https://www.planet.com/data/stac/catalog.json'
cat = intake.open_stac_catalog(catalog_url)

collection = cat['planet-disaster-data']
subset = collection['hurricane-harvey']['hurricane-harvey-0831']
item = subset['Houston-East-20170831-103f-100d-0f4f-RGB']

da = item['mosaic'].to_dask()
```

Before we address this issue by updating Intake-STAC, a quick solution is to downgrade xarray, for example:
```
pip install intake-stac xarray==2022.12.0
```

Start with the minimum reproducible example using intake.open_stac_catalog and item['mosaic'].to_dask(), then trace where Intake-STAC invokes the deprecated xarray.open_rasterio() method. Update the loading path so the example works without that deprecated method, and rerun it against the geotiff/COG item to verify the error is resolved.

Written by the indexing model from the issue text.