[Bug]: Linux VFS, right-click menu incomplete, only folders with files can be made `Always available locally`

### ⚠️ 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

The right-click menu of a folder is only complete if that folder contains a file. If it contains no files, the menu is incomplete - even if it contains an empty folder.

Folders without files can therefore not be made "always available locally".

Here are two screenshots, one of a folder with an empty file inside and one of an empty folder:


I understand that oftentimes this is not an issue, since there are no files to be made available locally. But there are cases where one would need that option: e.g. if one wants to prepare a folder for future usage, so that all future files are available locally, then this is not possible.

### Steps to reproduce

1. install `nextcloud-desktop`, `nextcloud-desktop-vfs-plugin`, and `nautilus-extension-nextcloud` packages
2. configure nextcloud.cfg according to instructions
3. configure a sync connection
4. create a folder and leave it empty
5. right-click on that folder, then click on the Nextcloud menu
6. not all options appear
7. now create a file inside that folder
8. right-click on that folder again
9. now all options are available

### Expected behavior

Whether a folder is empty or not, all options should be available.

### Which files are affected by this bug

all folders that do not have files in them

### Operating system

Linux

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

OpenSUSE Tumbleweed

### Package

Distro package manager

### Nextcloud Server version

29.0.4

### Nextcloud Desktop Client version

3.13.3

### 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 Disabled

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

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

### Nextcloud Server logs

_No response_

### Additional info

_No response_