chore(deps): bump SixLabors.ImageSharp in /Intersect.Server

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 3.0.2 to 3.1.5.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v3.0.2...v3.1.5)

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Intersect.Server/Intersect.Server.csproj

@@ -126,7 +126,7 @@
     <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="8.0.2" />
     <PackageReference Include="Pomelo.JsonObject" Version="2.2.1" />
     <PackageReference Include="Remotion.Linq" Version="2.2.0" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="3.0.2" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.5.0" />
     <PackageReference Include="Swashbuckle.AspNetCore.Newtonsoft" Version="7.2.0" />
     <PackageReference Include="Swashbuckle.AspNetCore.SwaggerGen.ConventionalRouting" Version="4.3.0" />