Bump ImageSharp to 3.1.5

https://github.com/advisories/GHSA-63p8-c4ww-9cg7

src/NzbDrone.Core/Lidarr.Core.csproj

@@ -25,7 +25,7 @@
     <PackageReference Include="TagLibSharp-Lidarr" Version="2.2.0.27" />
     <PackageReference Include="Npgsql" Version="7.0.7" />
     <PackageReference Include="SpotifyAPI.Web" Version="5.1.1" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.4" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5" />
     <PackageReference Include="Equ" Version="2.3.0" />
     <PackageReference Include="MonoTorrent" Version="2.0.7" />
   </ItemGroup>