Bump SixLabors.ImageSharp from 3.1.5 to 3.1.6 in /ImperatorToCK3

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 3.1.5 to 3.1.6.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v3.1.5...v3.1.6)

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

ImperatorToCK3/ImperatorToCK3.csproj

@@ -49,7 +49,7 @@
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
-        <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5"/>
+        <PackageReference Include="SixLabors.ImageSharp" Version="3.1.6"/>
     </ItemGroup>
 
     <ItemGroup>