Remove unnecessary VersionOverride for System.Security.Cryptography.Pkcs

The NuGet.Protocol project gets this dependency transitively through
NuGet.Packaging, and the central version in Directory.Packages.props
already specifies the correct version.

Author: JamieMagee

nuget/helpers/lib/NuGetUpdater/NuGetProjects/NuGet.Protocol/NuGet.Protocol.csproj

@@ -15,7 +15,6 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Security.Cryptography.Pkcs" VersionOverride="10.0.3" />
     <EmbeddedResource Include="$(NuGetSourceLocation)\src\NuGet.Core\NuGet.Protocol\**\*.resx" />
   </ItemGroup>