Discuss STAC extension dependencies in load_stac for assets with time dimension

[VincentVerelst]

Currently the load_stac process requires both the item_assets and datacube STAC extensions in order to be able to detect whether or not an asset has a time dimension.

When these extensions are not present in the STAC collection, the job will still run successfully, but the end result will not have a time dimension anymore.

Some questions:

• Why do we rely on two different extensions? Would for example only relying on item_assets not be enough?
• Could it be an option to throw a warning if one or two of these STAC extensions are not detected in the collection metadata?
• As of STAC 1.1 item_assets will be deprecated (https://github.com/stac-extensions/item-assets) and become part of the core spec. I guess in this case we would not need to rely on optional STAC extensions anymore to detect a time dimension in the assets, correct?