Enable 2FA Required in the npm organization of pkgjs

[bjohansebas]

I just noticed that the pkgjs organization does not have mandatory 2FA enabled. We should enable it and make it required.

I’m not sure if this has any side effects for members who don’t have 2FA enabled on npm, but if that’s the case, we should notify them and then activate the option

[ljharb]

Every package should also have 2FA enabled, and any owner on a package that matters already is required to enable 2FA, so we should just enable it.