Force System.Security.Cryptography.Pkcs dependency of EPPlus to version 6.0.0 (#675)

Issue: 96794

Author: sgrampone

dotnet/src/dotnetcore/GxExcel/GxExcel.csproj

@@ -18,6 +18,7 @@
   <ItemGroup>
     <PackageReference Include="EPPlus" Version="4.5.3.2" />
     <PackageReference Include="log4net" Version="2.0.11" />
+    <PackageReference Include="System.Security.Cryptography.Pkcs" Version="6.0.0" />
   </ItemGroup>
 
   <ItemGroup>