[Bug]: “Add Folder Sync Connection” causes a bad warning and duplicate files.

### ⚠️ Before submitting, please verify the following: ⚠️

- [X] This is a **bug**, not a question or a configuration issue.
- [X] This issue is **not** already reported on Github (I've searched it).
- [X] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [X] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

Adding a Folder Sync Connection causes an erroneous warning and results in the data being duplicated in the Nextcloud folder. This was mentioned long ago in [https://help.nextcloud.com/t/add-folder-sync-connection-creates-duplicate-copies-of-files/65762](https://help.nextcloud.com/t/add-folder-sync-connection-creates-duplicate-copies-of-files/65762).

### Steps to reproduce

1. Open Settings
2. Clock on "Add Folder Sync Connection"
3. Select a location. To best show my point, something like D:\TEST. (On a different drive than your Nextcloud folder.
4. On the "Select a remote destination folder" step, click "Create folder" and name it "TEST".
5. Here, you will see a warning that makes no sense. "**Warning:** you are already syncing /, which is a parent folder of /TEST."
6. Click "Next"
7. Uncheck "Use virtual files instead of downloading content immediately"
8. Click "Add Sync Connection"
9. A new sync "TEST" sync connection is created, but the "Nextcloud" sync connection now has a TEST folder that has synced back to your system and essentialy duplicated.
10. You must now uncheck the "TEST" folder under "Nextcloud" to remove the duplicate copy.
11. An alternative would be to create and uncheck the target folder prior to creating the new sync connection.

### Expected behavior

Adding a new sync should not automatically turn on replication in the Nextcloud folder.

### Which files are affected by this bug

Any that are defined this way.

### Operating system

Windows

### Which version of the operating system you are running.

Windows 11

### Package

Appimage

### Nextcloud Server version

28.0.2

### Nextcloud Desktop Client version

3.11.1

### Is this bug present after an update or on a fresh install?

Updated from a minor version (ex. 3.4.2 to 3.4.4)

### Are you using the Nextcloud Server Encryption module?

Encryption is Enabled

### Are you using an external user-backend?

- [X] Default internal user-backend
- [ ] LDAP/ Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

_No response_

### Additional info

[Nextcloud Client Debug.zip](https://github.com/nextcloud/desktop/files/14273923/Nextcloud.Client.Debug.zip)