Update seamless-scroll-polyfill to 1.2.3

[magic-akari]

No description provided.

[CLAassistant]

All committers have signed the CLA.

[JakeChampion]

Hi @magic-akari, thank you for the pull-request.

We've ran the tests on many browsers and some of them are failing, would you be able to fix these at all?

Failures:
 - ie/10.0:
    -> smoothscroll passes the feature detect
       false == true
 - ie/11.0:
    -> smoothscroll passes the feature detect
       false == true
 - ie/9.0:
    -> smoothscroll passes the feature detect
       false == true
 - ie/9.0:
    -> Element.prototype.inert inert set
       Unspecified error.

To run the tests:

• Build the polyfills with this command --> npm run build
• Run the testing server with this command --> node test/polyfills/server.js
• Open this url in the browser you want to test in --> http://bs-local.com:9876/test?includePolyfills=yes&always=no&feature=smoothscroll

[magic-akari]

It seems that the function Number.isNaN I used is not listed in the dependencies.
I have fixed it by removing this function.

[magic-akari]

I have fixed it. Would you mind rerun the tests?