DNS resolution of Server Address breaks when changing DNS Server during Sync Conflict

### ⚠️ 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

I'm not sure why but I was just banging my head against the wall with this issue for multiple hours and it immediately solved itself after resolving the sync conflict so I guess it must be a bug:
One of my colleagues' NC account had a sync conflict pending. The server is publically reachable via a CF Tunnel. I have a setup for my home network that uses Tailscale with Adguard as my DNS Server when I'm connected so my Server traffic can stay on the LAN. I was testing some networking stuff and had Tailscale off and noticed after a while that while my own Server's NC account reconnected the one of my colleague with the sync conflict didn't. I was also unable to connect to the NC Webpage on his server but ONLY on the windows machine that was in the sync conflict. All my other devices on the same network had no problem to connect.
I did some digging and with pfSense packet capture I discovered that when I tried to connect to the servers' domain it would try to connect to the tailscale address in order to look up the domain even though tailscale wasn't connected which obv didn't work. I tried restarting the PC and my router multiple times and even completely reset my Windows Network but to no avail - until I decided to reconnect to tailscale and noticed the sync conflict, resolved it and immediately I was able to connect to both the client and the webpage with and without Tailscale again. Not sure if that's a Tailscale problem in particular or if this applies to all variations of trying to switch DNS Server during an unresolved sync conflict but since it caused my entire PC to somehow not be able to connect to the server (not just the desktop client) I thought I'd share my findings! :)

### Steps to reproduce

1. Cause some sort of sync conflict while connected to DNS Server through Tailscale
2. Exit Tailscale without having resolved the conflict
3. Find yourself unable to connect to the server at all, systemwide

### Expected behavior

I think the server should still connect and then prompt you to resolve the sync conflict, regardless of which DNS server you use.

### Which files are affected by this bug

ALL

### Operating system

Windows

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

Windows 11

### Installation method

Official Windows MSI

### Nextcloud Server version

33.0.7

### 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?

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

### Nextcloud Server logs

```shell

```

### Additional info

_No response_

No affected files, tests, logs, or entry points are identified; the report only points to the Windows desktop client and the sync-conflict flow. Start by reproducing the three listed steps on Windows with Tailscale DNS, then compare connectivity before and after resolving the conflict. Done means the client and server remain reachable after switching DNS without resolving the conflict.

Written by the indexing model from the issue text.