adapt wix version also here to 7.0.0, related to change

Revision: 49c7e40
Author: chcg <christian.grasser@live.de>
Date: 12.04.2026 22:03:18
Message:
python 3.14.4 (#414)

Author: chcg

installer/buildInstaller.bat

@@ -51,7 +51,7 @@ SET /p PYTHONSCRIPTVERSION= < %INST_TEMP_DIR%\version.txt
 
 cd ..\packages
 echo add UI extension globally
-wix extension add -g WixToolset.UI.wixext/6.0.2
+wix extension add -g WixToolset.UI.wixext/7.0.0
 wix extension list -g
 cd ..\installer