hotfix: revert shadow plugin upgrade

[PierreSchwang]

Overview

Reverts commit a6da595. "Tree-Shaking" and shading itself doesn't seem to work reliable. Needs further investigation, but a working build is more important now.

Submitter Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
• New public fields and methods are annotated with @since TODO.
• I read and followed the contribution guidelines.