Bump externals/sgdk from 5841032 to 8ac6b85 (#561)

Bumps [externals/sgdk](https://github.com/Stephane-D/SGDK) from `5841032` to `8ac6b85`.
- [Release notes](https://github.com/Stephane-D/SGDK/releases)
- [Commits](Stephane-D/SGDK@5841032...8ac6b85)

---
updated-dependencies:
- dependency-name: externals/sgdk
  dependency-type: direct:production
...

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