Upload endpoint does not trigger index update

[simonbohnen]

The /channels/{channel_name}/upload/{filename} endpoint doesn't seem to trigger an index update, like the standard package upload does:

quetz/quetz/main.py

Lines 1335 to 1337 in 6cdf96e

	wrapped_bg_task = background_task_wrapper(indexing.update_indexes, logger)
	# Background task to update indexes
	background_tasks.add_task(wrapped_bg_task, dao, pkgstore, package.channel_name)

Because of that, trying to install an uploaded package (e.g. using mamba) fails as the package cannot be found. This seems to have happened because this endpoint (as opposed to the /channels/{channel_name}/packages/{package_name}/files/ endpoint) is untested.