Bump SixLabors.ImageSharp from 2.1.7 to 2.1.8 in /VTOL_2.0.0

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 2.1.7 to 2.1.8.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v2.1.7...v2.1.8)

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

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

VTOL_2.0.0/VTOL.csproj

@@ -362,7 +362,7 @@
     <PackageReference Include="Serilog.Settings.Configuration" Version="3.4.0" />
     <PackageReference Include="Serilog.Sinks.FastConsole" Version="2.3.0" />
     <PackageReference Include="Serilog.Sinks.File" Version="5.0.0" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.7" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.8" />
     <PackageReference Include="Syncfusion.SfTreeView.WPF" Version="21.2.3" />
     <PackageReference Include="System.Drawing.Common" Version="8.0.3" />
     <PackageReference Include="System.Management" Version="8.0.0" />