Update Rdmp.UI.csproj

Remove obsolete System.Threading.AccessControl package ref

Author: jas88

Rdmp.UI/Rdmp.UI.csproj

@@ -51,7 +51,6 @@
     <PackageReference Include="Scintilla.NET" Version="5.3.2.9" />
     <PackageReference Include="System.Security.Permissions" Version="7.0.0" />
     <PackageReference Include="System.Resources.Extensions" Version="7.0.0" />
-    <PackageReference Include="System.Threading.AccessControl" Version="8.0.0" />
     <PackageReference Include="VPKSoft.ScintillaLexers.NET" Version="1.1.16" />
     <PackageReference Include="WeCantSpell.Hunspell" Version="4.1.0" />
   </ItemGroup>