chore(deps): bump SixLabors.ImageSharp in /ShareBook/ShareBook.Helper

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 2.1.8 to 2.1.9.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v2.1.8...v2.1.9)

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

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

ShareBook/ShareBook.Helper/ShareBook.Helper.csproj

@@ -7,7 +7,7 @@
   <ItemGroup>
     <PackageReference Include="AutoMapper" Version="13.0.1" />
     <PackageReference Include="Microsoft.AspNetCore.Cryptography.KeyDerivation" Version="8.0.4" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.8" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.9" />
   </ItemGroup>
   <ItemGroup>
     <Folder Include="ClientVersionValidation\" />