Remove the Gamepad() constructor subfeature (#6664)
Remove the Gamepad() constructor subfeature (#6664)

This was added in https://github.com/mdn/browser-compat-data/pull/1760.

However, there's no constructor in https://w3c.github.io/gamepad/#gamepad-interface
and it appears there never was from the spec repo's history. One gets
Gamepad objects from `navigator.getGamepads()` and can't create them.

That browsers also don't support the constructor was verified by their
absense in source code:
 - Chromium: https://chromium.googlesource.com/chromium/src/+/9b50996d6e44f8b5140c33758be20d5a687a8eae/third_party/blink/renderer/modules/gamepad/gamepad.idl
 - Gecko: https://hg.mozilla.org/mozilla-central/file/f22c20641704d783097b1b128d826c8460de7354/dom/webidl/Gamepad.webidl
 - WebKit: https://trac.webkit.org/browser/webkit/trunk/Source/WebCore/Modules/gamepad/Gamepad.idl?rev=266799

Additionally, `new Gamepad()` was tested in Chrome 85, Edge 18, Firefox
80 and Safari 13.1, and found to throw the same error as for another
non-constructor, `new MediaError()`:
https://software.hixie.ch/utilities/js/live-dom-viewer/saved/8445
mdn/browser-compat-data,chrisdavidmills/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data