Upgrade to Qt6

[kassane]

cc: @jubal-R

-- The CXX compiler identification is GNU 13.2.1
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Performing Test HAVE_STDATOMIC
-- Performing Test HAVE_STDATOMIC - Success
-- Found WrapAtomic: TRUE  
-- Found OpenGL: /usr/lib/libOpenGL.so   
-- Found WrapOpenGL: TRUE  
-- Found XKB: /usr/lib/libxkbcommon.so (found suitable version "1.6.0", minimum required is "0.5.0") 
-- Found WrapVulkanHeaders: /usr/include  
-- The following OPTIONAL packages have been found:

 * Qt6CoreTools (required version >= 6.6.0)
 * Qt6Core
 * Qt6WidgetsTools (required version >= 6.6.0)
 * OpenGL
 * PkgConfig
 * XKB (required version >= 0.5.0), XKB API common to servers and clients., <http://xkbcommon.org>
 * Vulkan
 * WrapVulkanHeaders
 * Qt6GuiTools (required version >= 6.6.0)
 * Qt6DBusTools (required version >= 6.6.0)
 * Qt6Widgets
 * Qt6Core5Compat

-- The following REQUIRED packages have been found:

 * Qt6

-- Configuring done (0.8s)
-- Generating done (0.0s)
-- Build files have been written to: /home/kassane/Documentos/Geist/build
[  9%] Automatic MOC and UIC for target Geist
[  9%] Built target Geist_autogen
[ 63%] Building CXX object CMakeFiles/Geist.dir/src/search.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/src/utils/templates.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/src/main.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/src/utils/conversion.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/src/mainwindow.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/src/files.cpp.o
[ 72%] Building CXX object CMakeFiles/Geist.dir/Geist_autogen/mocs_compilation.cpp.o
[ 81%] Building CXX object CMakeFiles/Geist.dir/src/highlighter.cpp.o
[ 90%] Building CXX object CMakeFiles/Geist.dir/src/widgets/geisttextedit.cpp.o
[100%] Linking CXX executable bin/Geist
[100%] Built target Geist