Fix warning: remove unused parameter

Pick-to: 6.6 6.5
Change-Id: I5794e38e1e9871f14c9a8df6483e57c1922dace2
Reviewed-by: Jøger Hansegård <joger.hansegard@qt.io>
Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>
Reviewed-by: Pavel Dubsky <pavel.dubsky@qt.io>
(cherry picked from commit 8424a6401469fdfb9fbaad488fdd5fe65050f34a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

tests/auto/corelib/tools/quniquehandle/tst_quniquehandle.cpp

@@ -248,7 +248,7 @@ private slots:
         {
             using Type = int;
 
-            static bool close(Type handle)
+            static bool close(Type)
             {
                 return true;
             }