Fix some warnings

Change-Id: Idc12465aa6a3a3d158f17961f902578ca16d0d7b
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/qmljs/qmljsevaluate.cpp

@@ -213,6 +213,7 @@ bool Evaluate::visit(AST::UiQualifiedId *ast)
 
 bool Evaluate::visit(AST::TemplateLiteral *ast)
 {
+    Q_UNUSED(ast)
     _result = _valueOwner->stringValue();
     return false;
 }