[TSC] Adopt OpenJS's ESP (Ecosystem Sustainability Program)

As members of the OpenJS Foundation, we're covered on OpenJS's ESP program. Under the ESP program we could defer maintenance of our EoL versions (such as Webpack 4) and in the near future Webpack 5 once Webpack 6 releases, to our ESP partner, HeroDevs.

This would remove the burden on us for providing critical security patches to EoL versions and keep them running/alive for an indefinite amount of time through HeroDev's (https://herodevs.com) NES program (Never-Ending-Support)

This would also share the revenue from contracts closed by HeroDevs for Webpack 4/Webpack 5 EoL support directly to us. Allowing us to have extra resources to allocate on the critical work of maintaining our current active release lines.

OpenJS's Board of Directors member Jordan Harband (@ljharb) can provide more details and help us making this happen in case we're interested on it.