Remove reference assemblies that are added to the vsix

[pranavkm]

List of files inside the package:

• catalog.json
• Esent.Interop.dll
• extension.vsixmanifest
• manifest.json
• Microsoft.AspNetCore.Razor.Evolution.dll
• Microsoft.CodeAnalysis.Elfie.dll
• Microsoft.CodeAnalysis.Razor.Workspaces.dll
• Microsoft.CodeAnalysis.Remote.Razor.dll
• Microsoft.VisualStudio.LanguageServices.Razor.dll
• Microsoft.VisualStudio.RazorExtension.dll
• Microsoft.VisualStudio.RazorExtension.pdb
• Microsoft.VisualStudio.RazorExtension.pkgdef
• razorLanguageService.servicehub.service.json
• System.AppContext.dll
• System.Console.dll
• System.Diagnostics.FileVersionInfo.dll
• System.Diagnostics.StackTrace.dll
• System.IO.Compression.dll
• System.IO.FileSystem.dll
• System.IO.FileSystem.Primitives.dll
• System.Runtime.InteropServices.RuntimeInformation.dll
• System.Security.Cryptography.Algorithms.dll
• System.Security.Cryptography.Encoding.dll
• System.Security.Cryptography.Primitives.dll
• System.Security.Cryptography.X509Certificates.dll
• System.Text.Encoding.CodePages.dll
• System.Threading.Thread.dll
• System.ValueTuple.dll
• System.Xml.ReaderWriter.dll
• System.Xml.XmlDocument.dll
• System.Xml.XPath.dll
• System.Xml.XPath.XDocument.dll
• [Content_Types].xml

Most of the System.* binaries are reference assemblies and should not be required to be included in the package.