enable async bulk endpoint

[vincentsarago]

stac-fastapi/stac_fastapi/extensions/stac_fastapi/extensions/third_party/bulk_transactions.py

Lines 83 to 85 in 5060501

	endpoint=create_sync_endpoint(
	self.client.bulk_item_insert, items_request_model
	),

FYI: I'm working on a pgstac bulk loader ;-)