Update CoreJS to version 3

[Michael-1]

obsolete-web depends on @babel/runtime-corejs2 which is “no longer maintained and not recommended for usage due to the number of issues,” according to its install message.

Please update to version 3 of Core JS.

[Yegorich555]

Looks like the package hasn't been supported anymore. We have an improved/refactored version for webpack 5: https://github.com/AndrushkevichMikita/webpack-obsolete-plugin