build: updated anglesharp.css dependency

Author: egil

src/Directory.Build.props

@@ -13,6 +13,6 @@
 
   <ItemGroup>
     <PackageReference Include="AngleSharp" Version="0.15.0" />
-    <PackageReference Include="AngleSharp.Css" Version="0.14.2" />
+    <PackageReference Include="AngleSharp.Css" Version="0.15.0" />
   </ItemGroup>
 </Project>