Update workbox-webpack-plugin to strip deprecated core-js@2.6.11

[mahnunchik]

Is your proposal related to a problem?

Update workbox-webpack-plugin to strip deprecated core-js@2.6.11.

Describe the solution you'd like

└─┬ react-scripts@3.4.0
  └─┬ workbox-webpack-plugin@4.3.1
    └─┬ workbox-build@4.3.1
      └─┬ strip-comments@1.0.2
        └─┬ babel-plugin-transform-object-rest-spread@6.26.0
          └─┬ babel-runtime@6.26.0
            └── core-js@2.6.11

https://www.npmjs.com/package/workbox-webpack-plugin

[doc-duncan]

To avoid this warning I think workbox-webpack-plugin would have to jump all the way to v6x because v5x still depends on a workbox-build v5x which depends on strip-comments@1.0.2 still, as shown here

However, workbox-build v6x depends on strip-comments@2.0.1 which does not have the babel-plugin-transform-object-rest-spread dependency

workbox-build v6x package.json

strip-comments v2x package.json

update

After some further digging I found this issue and pr that was added to v2x of strip-comments but is a simple fix I would think to remediate that dependency.