cmake: Remove more Qt 5 code

Qt Gui virtualkeyboard plugin was removed in Qt 6.x.
Qt Network Bearer Management was removed in Qt 6.0.
Qt Multimedia mediaservice and audio plugins were removed in Qt 6.x.

cmake/common/helpers_common.cmake

@@ -255,10 +255,8 @@ function(find_qt_plugins)
   # cmake-format: off
   list(APPEND qt_plugins_Core platforms printsupport styles imageformats iconengines)
   # cmake-format: on
-  list(APPEND qt_plugins_Gui platforminputcontexts virtualkeyboard)
-  list(APPEND qt_plugins_Network bearer)
+  list(APPEND qt_plugins_Gui platforminputcontexts)
   list(APPEND qt_plugins_Sql sqldrivers)
-  list(APPEND qt_plugins_Multimedia mediaservice audio)
   list(APPEND qt_plugins_3dRender sceneparsers geometryloaders)
   list(APPEND qt_plugins_3dQuickRender renderplugins)
   list(APPEND qt_plugins_Positioning position)

cmake/macos/helpers.cmake

@@ -450,7 +450,7 @@ function(_bundle_dependencies target)
         continue()
       endif()
 
-      if(library MATCHES "Qt[56]?::.+")
+      if(library MATCHES "Qt6?::.+")
         find_qt_plugins(COMPONENT ${library} TARGET ${target} FOUND_VAR plugins_list)
       endif()
       list(APPEND library_paths ${library_location})

cmake/windows/helpers.cmake

@@ -402,7 +402,7 @@ function(_bundle_dependencies target)
         endif()
       endforeach()
 
-      if(library MATCHES "Qt[56]?::.+")
+      if(library MATCHES "Qt6?::.+")
         find_qt_plugins(COMPONENT ${library} TARGET ${target} FOUND_VAR plugins_list)
       endif()
     endif()