Fix project duration label displaying one frame too much

BUG: 425639

src/mainwindow.cpp

@@ -2206,11 +2206,11 @@ void MainWindow::slotUpdateMousePosition(int pos)
         switch (m_timeFormatButton->currentItem()) {
         case 0:
             m_timeFormatButton->setText(pCore->currentDoc()->timecode().getTimecodeFromFrames(pos) + QStringLiteral(" / ") +
-                                        pCore->currentDoc()->timecode().getTimecodeFromFrames(getMainTimeline()->controller()->duration()));
+                                        pCore->currentDoc()->timecode().getTimecodeFromFrames(getMainTimeline()->controller()->duration() - 1));
             break;
         default:
             m_timeFormatButton->setText(
-                QStringLiteral("%1 / %2").arg(pos, 6, 10, QLatin1Char('0')).arg(getMainTimeline()->controller()->duration(), 6, 10, QLatin1Char('0')));
+                QStringLiteral("%1 / %2").arg(pos, 6, 10, QLatin1Char('0')).arg(getMainTimeline()->controller()->duration() - 1, 6, 10, QLatin1Char('0')));
         }
     }
 }