main: Globally disable the "?" button on dialogs

Sets the AA_DisableWindowContextHelpButton attribute to disable this useless button globally.

src/yuzu/util/sequence_dialog/sequence_dialog.cpp

@@ -8,7 +8,6 @@
 
 SequenceDialog::SequenceDialog(QWidget* parent) : QDialog(parent) {
     setWindowTitle(tr("Enter a hotkey"));
-    setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
 
     key_sequence = new QKeySequenceEdit;