Bump WPFUI version to preview-13 to fix scrollbar issue

[niels9001]

Summary of the Pull Request

This PR bumps WPFUI to preview-13. It contains a scrollbar fix, so that we can now fix: #30318 and #30862

Before:

After:

PR Checklist

• Closes: Missing margins in PowerToys Run results  #30318, Misaligned scrol bar #30862
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Validation Steps Performed

[jaimecbernardo]

Might this fix #30862 as well?

[niels9001]

Might this fix #30862 as well?

Ah yes, that is correct! I fixed that in the same PR for the scrollbar position. Will tag that issue as well.

[jaimecbernardo]

Hi,
Thanks for opening this PR.
CI has been failing on the PR due to an update to .NET 8.0.1 in the CI machines. This should've been fixed in #30892 , which was just merged.
Can you please merge main in your PR so that CI can run correctly?
Thank you 😄

[niels9001]

Hi, Thanks for opening this PR. CI has been failing on the PR due to an update to .NET 8.0.1 in the CI machines. This should've been fixed in #30892 , which was just merged. Can you please merge main in your PR so that CI can run correctly? Thank you 😄

Done!

[jaimecbernardo]

LGTM! Thank you for the contribution!