Fix webpack configuration for Gitpod GDK

The following discussion from !43103 (merged) should be addressed:

• @mvanremmerden started a discussion: (+3 comments)

  @corneliusludmann @ashmckenzie After applying all suggestions, I'm also seeing this error message pop up way more often than ever before.

  

  It goes away after waiting 30-40 seconds and reloading, but any idea what could have caused this, or how we could fix this?

@corneliusludmann You mentioned you had already worked on a first fix for this. Would it be possible to try that out, we are getting more and more reports of this now, and it's tough for users to figure out how to fix this. I'm also easily available tomorrow, so we can look into it together if that might help 🙂

~bug UX Category:GDK ~"group::ecosystem" devopscreate sectiondev