[runner] removed outdated MSIX code

[enricogior]

Summary of the Pull Request

What is this about:
Clean up runner's outdated code.

What is include in the PR:
Remove outdated code that was detecting the MSIX version

How does someone test / validate:
Test the core main functionality at startup:

• check if when a second instance is started, the Settings app is opened
• check that a toast notification is correctly handled
• check that a first time run opens OOBE

Quality Checklist

• Linked issue: [runner] clean up startup procedure #11352
• Communication: I've discussed this with core contributors in the issue.
• Tests: Added/updated and all pass
• Installer: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Docs: Added/ updated
• Binaries: Any new files are added to WXS / YML
  • No new binaries
  • YML for signing for new binaries
  • WXS for installer for new binaries

Contributor License Agreement (CLA)

A CLA must be signed. If not, go over here and sign the CLA.

[crutkas]

@yuyoyuppe any reason to not merge this in?