Description of problem:
Very quickly closing the window produced by `plasma-discover --backends packagekit appstream://org.kde.dolphin.desktop` (whilst it's still loading metadata, if relevant) always causes a it to segmentation fault:

> ~~~
> plasma-discover --backends packagekit appstream://org.kde.dolphin.desktop
> org.kde.plasma.libdiscover: OdrsReviewsBackend: Fetch ratings: false
> adding empty sources model QStandardItemModel(0x55faeda87780)
> qrc:/qt/qml/org/kde/discover/qml/LoadingPage.qml:3:1: QML LoadingPage: Created graphical object was not placed in the graphics scene.
> 
> ** (process:148294): WARNING **: 16:53:41.899: Found icon of unknown type 'unknown' in 'system/package/os/org.luanti.luanti/*', skipping it.
> KCrash: Application 'plasma-discover' crashing... crashRecursionCounter = 2
> Segmentation fault (core dumped)
> ~~~

Version-Release number of selected component:
plasma-discover-6.3.5-1.fc42

Additional info:
reporter:       libreport-2.17.15
type:           CCpp
reason:         plasma-discover killed by SIGSEGV
journald_cursor: s=c1f108f1ef4e48808a377c0a73f168fc;i=6b032c;b=98a120a258d04198a51294d98f8a95b6;m=3bf755825;t=637760cfb39d9;x=fc1f3a666e715a2e
executable:     /usr/bin/plasma-discover
cmdline:        plasma-discover --backends packagekit appstream://org.kde.dolphin.desktop
cgroup:         0::/user.slice/user-1000.slice/user/app.slice/app-dev.warp.WarpPreview
rootdir:        /
uid:            1000
kernel:         6.14.9-300.fc42.x86_64
package:        plasma-discover-6.3.5-1.fc42
runlevel:       N 5
backtrace_rating: 4
crash_function: KCrash::defaultCrashHandler

Truncated backtrace:
Thread no. 1 (30 frames)
 #3 KCrash::defaultCrashHandler at /usr/src/debug/kf6-kcrash-6.14.0-1.fc42.x86_64/src/kcrash.cpp:605
 #5 QtPrivate::QMetaTypeInterfaceWrapper<QObject*>::metaType
 #6 AbstractResource::isInstalled at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/libdiscover/resources/AbstractResource.cpp:71
 #7 operator()<StreamResult> at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/discover/DiscoverObject.cpp:366
 #8 kIndexOf<QList<StreamResult>, DiscoverObject::openApplication(const QUrl&)::<lambda()>::<lambda(QVector<StreamResult>&)>::<lambda()>::<lambda(auto:56)> > at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/libdiscover/utils.h:123
 #9 operator() at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/discover/DiscoverObject.cpp:365
 #10 std::__invoke_impl<bool, DiscoverObject::openApplication(const QUrl&)::<lambda()>::<lambda(QVector<StreamResult>&)>::<lambda()>&> at /usr/include/c++/15/bits/invoke.h:63
 #11 std::__invoke_r<bool, DiscoverObject::openApplication(const QUrl&)::<lambda()>::<lambda(QVector<StreamResult>&)>::<lambda()>&> at /usr/include/c++/15/bits/invoke.h:116
 #12 std::_Function_handler<bool(), DiscoverObject::openApplication(const QUrl&)::<lambda()>::<lambda(QVector<StreamResult>&)>::<lambda()> >::_M_invoke(const std::_Any_data &) at /usr/include/c++/15/bits/std_function.h:292
 #13 std::function<bool()>::operator() at /usr/include/c++/15/bits/std_function.h:593
 #14 OneTimeAction::trigger at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/libdiscover/utils.h:39
 #16 QtPrivate::QSlotObjectBase::call at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobjectdefs_impl.h:461
 #17 doActivate<false> at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:4146
 #18 QMetaObject::activate at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:4206
 #19 QMetaObject::activate<void, QObject*> at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobjectdefs.h:306
 #20 QObject::destroyed at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/redhat-linux-build/src/corelib/kernel/moc_qobject.cpp:186
 #21 QObject::~QObject at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:1042
 #22 QTimer::~QTimer at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qtimer.cpp:138
 #23 QObjectPrivate::deleteChildren at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:2223
 #24 QObject::~QObject at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:1140
 #25 DiscoverObject::~DiscoverObject at /usr/src/debug/plasma-discover-6.3.5-1.fc42.x86_64/discover/DiscoverObject.cpp:228
 #26 QObject::event at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qobject.cpp:1416
 #27 QApplicationPrivate::notify_helper at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/widgets/kernel/qapplication.cpp:3303
 #28 QCoreApplication::notifyInternal2 at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qcoreapplication.cpp:1106
 #29 QCoreApplication::sendEvent at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qcoreapplication.cpp:1546
 #30 QCoreApplicationPrivate::sendPostedEvents at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qcoreapplication.cpp:1879
 #31 QCoreApplicationPrivate::execCleanup at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/kernel/qcoreapplication.cpp:1468
 #32 QCoreApplication::exec at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/corelib/tools/qscopedpointer.h:110
 #33 QGuiApplication::exec at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/gui/kernel/qguiapplication.cpp:1986
 #34 QApplication::exec at /usr/src/debug/qt6-qtbase-6.9.1-1.fc42.x86_64/src/widgets/kernel/qapplication.cpp:2570