Bump jszip, @microsoft/sp-build-web and @microsoft/sp-webpart-workbench

Bumps [jszip](https://github.com/Stuk/jszip), [@microsoft/sp-build-web](http://aka.ms/spfx) and [@microsoft/sp-webpart-workbench](http://aka.ms/spfx). These dependencies needed to be updated together.

Updates `jszip` from 2.5.0 to 3.7.1
- [Release notes](https://github.com/Stuk/jszip/releases)
- [Changelog](https://github.com/Stuk/jszip/blob/main/CHANGES.md)
- [Commits](Stuk/jszip@v2.5.0...v3.7.1)

Updates `@microsoft/sp-build-web` from 1.11.0 to 1.15.2

Updates `@microsoft/sp-webpart-workbench` from 1.11.0 to 1.12.1

---
updated-dependencies:
- dependency-name: jszip
  dependency-type: indirect
- dependency-name: "@microsoft/sp-build-web"
  dependency-type: direct:development
- dependency-name: "@microsoft/sp-webpart-workbench"
  dependency-type: direct:development
...

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