Remove some unused usings

tools/Tgstation.Server.ReleaseNotes/Program.cs

@@ -4,21 +4,17 @@ using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.IdentityModel.Tokens.Jwt;
 using System.IO;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Sockets;
 using System.Security;
-using System.Security.Cryptography;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using System.Xml.Linq;
 
-using Microsoft.IdentityModel.Tokens;
-
 using Newtonsoft.Json;
 
 using Octokit;