Remove polyfill service in OpenCV.docset and others

[zhouzq-thu]

In OpenCV.docset 4.10, the html contains

<script src="https://polyfill.io/v3/polyfill.min.js?features=es6"></script>

However, polyfill contains malicious content see

• https://github.com/polyfillpolyfill/polyfill-service
• Formerly legitimate Polyfill.io domain abused to serve malicious code

[Kapeli]

Thanks for letting me know about this. I've removed it and will also check other docsets for it.