Attempting to add the everyone role to a user causes 404

[Still34]

Title.
Reproducible using

        [Command("role-test")]
        public async Task RoleAddTest()
        {
            if (Context.User is SocketGuildUser user)
                await user.AddRolesAsync(new []{ Context.Guild.Roles.FirstOrDefault(x => x.IsEveryone), Context.Guild.Roles.FirstOrDefault(x=>!x.IsEveryone)});
        }

Stack trace

      Command     Discord.Commands.CommandException: Error occurred executing "role-test" for Still#2876 in DevServer/nsfw-general. ---> Discord.Net.HttpException: The server responded with error 404: NotFound
         at Discord.Net.Queue.RequestBucket.<SendAsync>d__18.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.Net.Queue.RequestQueue.<SendAsync>d__14.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.API.DiscordRestApiClient.<SendInternalAsync>d__62.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.API.DiscordRestApiClient.<SendAsync>d__51.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.API.DiscordRestApiClient.<AddRoleAsync>d__73.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.Rest.UserHelper.<AddRolesAsync>d__4.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
         at GeneralBot.Commands.Owners.BotModule.<RoleAddTest>d__11.MoveNext() in C:\Users\34146\Source\Repos\GeneralBot\GeneralBot\Commands\Owners\BotModule.cs:line 42
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.Commands.ModuleClassBuilder.<>c__DisplayClass6_1.<<BuildCommand>g__ExecuteCallback1>d.MoveNext()
      --- End of stack trace from previous location where exception was thrown ---
         at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
         at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
         at Discord.Commands.CommandInfo.<ExecuteAsyncInternal>d__41.MoveNext()
         --- End of inner exception stack trace ---

This will also cause issues when adding roles whose collection contains the Everyone role (i.e. IGuildUser#AddRolesAsync()), the method will throw and exit immediately.
imo AddRoleAsync method should ignore the everyone role of the guild.

[foxbot]

It doesn't seem like it would be good design to just start throwing out invalid request parameters - if anything, we could add a precondition here to preemptively stop role modifications with the everyone role attached (as we do with the 14-day age limit on bulk delete)

[Still34]

I could see people accidentally adding EveryoneRole when filtering through the roles collection with LINQ - I know I did several times. I think adding a check on AddRoleAsync would be great.