Allow the Upload Field to specify multiple collections in relationTo

[immotus]

For some weird reason, the Upload Field only allows to specify a single collection in the relationTo property, e.g.:

{
	name: "image",
	type: "upload",
	relationTo: "assets",
	filterOptions: {
		mimeType: { contains: "image" },
	},
}

However, if you add a generic Upload block in a Lexical editor, it allows you to browse all your upload collections. Why can't I do something like:

{
	name: "image",
	type: "upload",
	relationTo: [ "assets", "media" ],
	filterOptions: {
		mimeType: { contains: "image" },
	},
}

Versions:
"payload": "^2.27.0",
"@payloadcms/bundler-webpack": "^1.0.7",
"@payloadcms/db-mongodb": "^1.7.2",
"@payloadcms/plugin-cloud-storage": "^1.1.3",
"@payloadcms/plugin-seo": "^2.3.2",
"@payloadcms/richtext-lexical": "^0.11.3",