Now it depends against new version. Old code can be removed

plugins/process/network/network.cpp

@@ -75,11 +75,7 @@ NetworkPlugin::NetworkPlugin(QObject *parent, const QVariantList &args)
             const QString line = QString::fromUtf8(m_process->readLine());
 
             // Each line consists of: timestamp|PID|pid|IN|in_bytes|OUT|out_bytes
-#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
-            const auto parts = line.splitRef(QLatin1Char('|'), QString::SkipEmptyParts);
-#else
             const auto parts = line.splitRef(QLatin1Char('|'), Qt::SkipEmptyParts);
-#endif
             if (parts.size() < 7) {
                 continue;
             }

plugins/process/nvidia/nvidia.cpp

@@ -79,11 +79,7 @@ void NvidiaPlugin::setup()
                 }
                 continue;
             }
-#if QT_VERSION < QT_VERSION_CHECK(5, 15, 0)
-            const auto parts = line.splitRef(QLatin1Char(' '),  QString::SkipEmptyParts);
-#else
             const auto parts = line.splitRef(QLatin1Char(' '),  Qt::SkipEmptyParts);
-#endif
 
             // format at time of writing is
             // # gpu        pid  type    sm   mem   enc   dec   command