build(deps): update Splat.Drawing requirement from 12.* to 13.* in /src (#2890)

Updates the requirements on [Splat.Drawing](https://github.com/reactiveui/splat) to permit the latest version.
- [Release notes](https://github.com/reactiveui/splat/releases)
- [Commits](reactiveui/splat@12.1.1...13.1.1)

---
updated-dependencies:
- dependency-name: Splat.Drawing
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]