Doc: Fix qdoc warnings

The following warnings are fixed:

qt5/qtvirtualkeyboard/src/styles/KeyboardStyle.qml:531: (qdoc) warning: Can't link to 'QtVirtualKeyboard.KeyboardFunction'
qt5/qtvirtualkeyboard/src/virtualkeyboard/content/InputPanel.qml:83: (qdoc) warning: Can't link to 'QtQml::Qt::locale()'
qt5/qtvirtualkeyboard/src/virtualkeyboard/doc/src/xt9.qdoc:28: (qdoc) warning: Can't link to 'QVirtualKeyboardDictionaryManager'
qt5/qtvirtualkeyboard/src/virtualkeyboard/doc/src/xt9.qdoc:28: (qdoc) warning: Can't link to 'VirtualKeyboardSettings.defaultDictionaryDisabled'

Task-number: QTBUG-95860
Change-Id: I34be6017bca7e1bd4cf1d8850181a72dec70e068
Reviewed-by: Jarkko Koivikko <jarkko.koivikko@code-q.fi>
(cherry picked from commit 4079ab86

)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>