QmlProfiler/PerfProfiler: Restore support for Qt >= 6.2

First (try to) add the target as Qt Creator plugin, *then* check whether
it exists.

Amends: 5aff1419fa

Change-Id: Ia7c318c0ffb7bbaa21159ddf9de88b80ad0033cb
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/perfprofiler/CMakeLists.txt

@@ -48,10 +48,6 @@ if(${Qt5_VERSION} VERSION_LESS "6.2.0")
       perfprofiler.qrc
   )
 else() # < Qt 6.2
-  if (NOT TARGET PerfProfiler)
-    return()
-  endif()
-
   add_qtc_plugin(PerfProfiler
     DEPENDS Tracing Qt5::QuickWidgets
     PLUGIN_DEPENDS Core Debugger ProjectExplorer QtSupport
@@ -59,6 +55,10 @@ else() # < Qt 6.2
       ${TEST_SOURCES}
   )
 
+  if (NOT TARGET PerfProfiler)
+    return()
+  endif()
+
   qt_add_resources(PerfProfiler perfprofiler
     PREFIX "/perfprofiler"
     tracepoints.sh

src/plugins/qmlprofiler/CMakeLists.txt

@@ -79,10 +79,6 @@ if(${Qt5_VERSION} VERSION_LESS "6.2.0")
       qml/qmlprofiler.qrc
   )
 else() # < Qt 6.2
-  if (NOT TARGET QmlProfiler)
-    return()
-  endif()
-
   add_qtc_plugin(QmlProfiler
     DEPENDS QmlDebug QmlJS Tracing Qt5::QuickWidgets
     PLUGIN_DEPENDS Core Debugger ProjectExplorer QtSupport TextEditor
@@ -90,6 +86,10 @@ else() # < Qt 6.2
       ${TEST_SOURCES}
   )
 
+  if (NOT TARGET QmlProfiler)
+    return()
+  endif()
+
   set(QMLPROFILER_QML_FILES
     qml/QmlProfilerFlameGraphView.qml
   )