Add CMakeUserPresets.json to .gitignore

The CMakeUserPresets.json file can be used to simplify configuring Qt,
particularly with tools such as Visual Studio and Visual Studio Code.

As opposed to the CMakePresets.json, the CMakeUserPresets.json should
only contain user specific configurations, and should never be checked
into source code management system.

This file is already ignored in the top level Qt super-project, but to
facilitate working with each individual submodule, we should also have
this .gitignore in each submodule.

Pick-to: 6.5 6.6
Change-Id: I383417c7fe9d803aeb0385ba83e8c9cee6181602
Reviewed-by: Miguel Costa <[email protected]>

.gitignore

@@ -333,3 +333,4 @@ CTestTestfile.cmake
 cmake_install.cmake
 *_autogen
 tst_*.xml
+CMakeUserPresets.json