[Reg 5.15->6.x] Crash and/or bad output when printing via Qt WebEngine's PDF plugin

Steps to reproduce

1. Load the WebEngine Widgets PrintMe Example (https://doc.qt.io/qt-6/qtwebengine-webenginewidgets-printme-example.html )
2. Modify main.cpp as follows:

   //view.setUrl(QUrl(QStringLiteral("qrc:/index.html")));
   QWebEngineProfile::defaultProfile()->settings()->setAttribute(QWebEngineSettings::PluginsEnabled, true);
   view.setUrl(QUrl("https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf"));

1. Build and run the project in Release mode
2. Press [Ctrl]+[Shift]+P to activate the print dialog
3. Select the "Microsoft Print To PDF" printer and print it to disk

Expected outcomes (5.15.15)

• The output file looks like a copy of dummy.pdf (see attached output-5.15.pdf)
• No crash

Actual outcomes (6.x)

• The output file looks like the Chromium PDF viewing pane, but doesn't contain the actual PDF content (see attached output-6.6.pdf)
• Qt 6.6.1 produces an error message in Release mode ("Invalid parameter passed to C runtime function") and crashes in Debug mode with the following backtrace:

  Received fatal exception EXCEPTION_BREAKPOINT
  Backtrace:
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF938029CE8+276867377]
  	invalid_parameter [0x00007FF970417EC6+406]
  	invalid_parameter [0x00007FF970417D90+96]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E868B88+386176977]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E8684FD+386175302]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E86855D+386175398]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E868431+386175098]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E86874A+386175891]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93E85A113+386116956]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F326B7+477180672]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F32A6B+477181620]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F38B1C+477206373]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F24C7B+477124804]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F2561C+477127269]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F269B0+477132281]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F3FAE6+477234991]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF92807E615+8778334]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F3067E+477172423]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F3232C+477179765]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F3942B+477208692]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F3CAB2+477222651]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937C73F9F+272976872]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF943F2CEF5+477158206]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93988ACDA+302430499]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF939888993+302421468]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF9398CB198+302693857]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93988A0A8+302427377]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93A362F2F+313801592]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93A356F0B+313752404]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93A357625+313754222]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93A357A60+313755305]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93A368336+313823103]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF92807E615+8778334]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937E2D637+274784896]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937FD31F7+276512320]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937FE6B35+276592510]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937FE5A3F+276588168]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937D74226+274026095]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937FF1438+276635777]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF937F814AD+276177142]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93EBCB1FD+389725766]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93639538C+246898645]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF936393F90+246893529]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF93638D0D1+246865178]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF936387D3D+246843782]
  	QWebEnginePage::setUrlRequestInterceptor [0x00007FF9280FF25E+9305767]
  	TargetGetStockObject [0x00007FF7ED2C49A3+287028]
  	TargetGetStockObject [0x00007FF7EDA46CE7+8160376]
  	TargetGetStockObject [0x00007FF7EDA46AEE+8159871]
  	TargetGetStockObject [0x00007FF7EDA3E492+8125475]
  	TargetGetStockObject [0x00007FF7EDA3E33E+8125135]
  	TargetGetStockObject [0x00007FF7EDA3E1FE+8124815]
  	TargetGetStockObject [0x00007FF7EDA3E52E+8125631]
  	BaseThreadInitThunk [0x00007FFA3AAB7344+20]
  	RtlUserThreadStart [0x00007FFA3C5226B1+33]

• Qt 6.2.10/6.5.3 might also crash if we click the "print" icon embedded in the PDF viewer