CMake: Don't include configure.cmake twice

The VirtualKeyboardQml module is defined in the same directory as
VirtualKeyboard. qt_internal_add_module includes the directory's
configure.cmake for both modules, so every feature, summary entry and
report note was evaluated twice, and the Hunspell note was printed
twice at the end of configure.

VirtualKeyboardQml has no C++ sources and does not need a config
header, so pass NO_CONFIG_HEADER_FILE.

Fixes: QTBUG-133246
Pick-to: 6.12
Change-Id: I67dfdc1c89107a2c893d05b1db8e518dc9610eb1
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>