fix: disable direct download for shares

[icewind1991]

I'm not aware of any storage backend that implements this but this still requires setting up the share source to forward the call currently.

Additionally I'm unsure if shares should even use the same direct download link as their source.

[artonge]

Not sure about the reason for such method in the first place. But isn't it the default anyway?

server/lib/private/Files/Storage/Common.php

Lines 452 to 454 in b90c7b3

	public function getDirectDownload(string $path): array|false {
	return [];
	}

[icewind1991]

But isn't it the default anyway?

For storage wrappers, it defaults to forwarding the call to the underlying storage. Which for shared storage means doing the full share setup.

[icewind1991]

/backport to stable31