Bump SixLabors.ImageSharp from 3.1.12 to 4.0.0

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

api/API/API.csproj

@@ -38,7 +38,7 @@
 
         <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="10.0.0" />
 
-        <PackageReference Include="SixLabors.ImageSharp" Version="3.1.12" />
+        <PackageReference Include="SixLabors.ImageSharp" Version="4.0.0" />
         <PackageReference Include="Soenneker.Utils.String.NeedlemanWunsch" Version="4.0.983" />
         <PackageReference Include="Swashbuckle.AspNetCore" Version="10.1.0" />
         <PackageReference Include="Swashbuckle.AspNetCore.Newtonsoft" Version="10.1.0" />