Duplicate teams in team folders team selection dialog

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Steps to reproduce

1. Log in as admin
2. Create a few teams as admin
3. Set the sole owner of a team to another team
4. Navigate to the team folders administration and try to set this team for a team folder

Expected behaviour

Duplicate entries will show (sometimes even more than two entries, couldn't figure out a pattern)

The GET request to https://[host]/apps/groupfolders/delegation/circles also shows duplicate entries:

{
	"ocs": {
		"meta": {
			"status": "ok",
			"statuscode": 100,
			"message": "OK",
			"totalitems": "",
			"itemsperpage": ""
		},
		"data": [
			{
				"singleId": "IbNdUdlXdIAbzzuZo2ILHActG8QaMkk",
				"displayName": "foo"
			},
			{
				"singleId": "IbNdUdlXdIAbzzuZo2ILHActG8QaMkk",
				"displayName": "foo"
			},
			{
				"singleId": "fJnwlTYjmxuJCPJQYG4HoFOTYxylgC7",
				"displayName": "bar"
			},
			{
				"singleId": "fJnwlTYjmxuJCPJQYG4HoFOTYxylgC7",
				"displayName": "bar"
			},
			[...]
		]
	}
}

Actual behaviour

Each team should only show once. The quick fix would probably be to remove duplicates here: https://github.com/nextcloud/groupfolders/blob/master/lib/Controller/DelegationController.php#L105

But it could also be that the original issue belongs to https://github.com/nextcloud/circles/

Server configuration

Database: PostgreSQL 17.6

PHP version: 8.3.25

Nextcloud version: 31.0.8

Team folders version: 19.1.3

Start in lib/Controller/DelegationController.php around line 105 and inspect the GET /apps/groupfolders/delegation/circles response. Reproduce the team-folder selection flow with a team whose sole owner is another team, then determine whether duplicates originate in groupfolders or circles. Done means each team appears once in the dialog and the endpoint data contains no duplicate entries.