Bump SixLabors.ImageSharp from 1.0.3 to 1.0.4 (#144)

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 1.0.3 to 1.0.4.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v1.0.3...v1.0.4)

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

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

Author: dependabot[bot]

PreviewThumbnailExtractor/PreviewThumbnailExtractor.csproj

@@ -8,7 +8,7 @@
   <ItemGroup>
     <PackageReference Include="LibVLCSharp" Version="3.5.0" />
     <PackageReference Include="VideoLAN.LibVLC.Windows" Version="3.0.16" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.3" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.4" />
   </ItemGroup>
 
 </Project>