UNC paths are not supported. Defaulting to Windows directory

### Apache NetBeans version

Apache NetBeans 26

### What happened

After upgrading from Netbeans 24 to Netbeans 26 my Maven project located on
mapped network drive stopped to build.
The reason is that network mapped drive is always referred by UNC Path.
As result starting build of project reports
"UNC paths are not supported. Defaulting to Windows directory."
After trying to change directory to UNC path instead of mapped drive path.
cd \\server\path to project
instead of
X:\path to project

I have tried different options to disable UNC path converting as -J-Duse.unc.paths=false -J-Duse.mapped.drives=true
but without success.

### Language / Project Type / NetBeans Component

_No response_

### How to reproduce

1. The problem exists in Windows 11 environment.
2. Create Simple Maven project on SMB (Windows share) mapped network drive x:\path\to\project.
3. Save project and exit from Netbeans.
4. Start netbeans again. After reopen project, the path is converted to UNC \\server\path\to\project.
5. The project can't be build.

### Did this work correctly in an earlier version?

No / Don't know

### Operating System

Windows 11

### JDK

JDK 24

### Apache NetBeans packaging

Apache NetBeans provided installer

### Anything else

_No response_

### Are you willing to submit a pull request?

No

Reproduce this on Windows 11 with a Simple Maven project stored on an SMB share mapped to a drive, then trace how reopening the project converts its path to UNC before the build starts. Done means the project can be reopened and built from the mapped network location without the UNC-path warning.

Written by the indexing model from the issue text.