macOS sync failure error -2005 triggered when files are opened

### ⚠️ 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 have searched for 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

When opening and editing .docx/.xlsx files from the local Nextcloud Desktop 34.0.1 sync folder on macOS 26.6, the client no longer uploads the saved changes to the server. Instead, the file remains unsynced and the client reports error -2005. This behaviour previously worked as expected in earlier versions.

### Steps to reproduce

1. Open a *.docx (or *.xlsx) file stored in the local Nextcloud sync folder
2. Edit the document but keep it open
3. Save the document
4. Nextcloud Desktop client fails to sync the changes
5. Do the same with a *.py or *.md document, changes to the document are being synced to the server

### Expected behavior

The client should detect the modified *.docx/.xlsx file, the updated file is uploaded to the server and no sync errors appear.

### Which files are affected by this bug

Microsoft, Apple, and other office documents

### Operating system

macOS

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

macOS Tahoe 26.6 (25G72)

### Installation method

Official Installer for macOS 13 and later

### Nextcloud Server version

34.0.3

### Nextcloud Desktop Client version

34.0.1

### Did this occur after an update or on a clean installation?

Minor version update (i.e. 33.0.0 → 33.0.1)

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

No

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

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

### Nextcloud Server logs

No log entries.

### Additional info

Happy to share the Desktop client logs if needed!

Start by reproducing the difference between open .docx/.xlsx files and .py/.md files in the macOS sync folder using Desktop 34.0.1, then inspect the Desktop client logs around error -2005. Done means saved office documents upload while still open and no sync error remains.

Written by the indexing model from the issue text.