Update dependency SixLabors.ImageSharp to v2

Author: renovate-bot

AstroBot/AstroBot.csproj

@@ -23,7 +23,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="NLog" Version="4.7.12" />
     <PackageReference Include="NLog.Extensions.Logging" Version="1.7.4" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="1.0.4" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="2.1.0" />
     <PackageReference Include="SixLabors.ImageSharp.Drawing" Version="1.0.0-beta13" />
   </ItemGroup>