v3: 238-branch: Data race with ws.sendLimiter

[1lann]

I got a data race (that I have not attempted to reproduce and does not reproduce on its own, I got a weird unauthorized error from the gateway) on 238-branch. Just noting it down here if you or I could investigate it later:

==================
WARNING: DATA RACE
Write at 0x00c000072120 by main goroutine:
  github.com/diamondburned/arikawa/v3/utils/wsutil.(*Websocket).Dial()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/utils/wsutil/ws.go:103 +0x316
  github.com/diamondburned/arikawa/v3/gateway.(*Gateway).Open()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/gateway/gateway.go:361 +0x139
  github.com/diamondburned/arikawa/v3/session.(*Session).Open()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/session/session.go:144 +0x1a4
  main.(*Bot).Start()
      K:/Douki/tmpphone/bot.go:71 +0xf2
  main.main()
      K:/Douki/tmpphone/main.go:125 +0x12ac

Previous read at 0x00c000072120 by goroutine 31:
  github.com/diamondburned/arikawa/v3/utils/wsutil.(*Websocket).SendCtx()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/utils/wsutil/ws.go:131 +0xf5
  github.com/diamondburned/arikawa/v3/gateway.(*Gateway).SendCtx()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/gateway/gateway.go:524 +0x229
  github.com/diamondburned/arikawa/v3/gateway.(*Gateway).UpdateVoiceStateCtx()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/gateway/commands.go:120 +0x293
  github.com/diamondburned/arikawa/v3/voice.(*Session).JoinChannelCtx()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/voice/session.go:212 +0x1e6
  github.com/diamondburned/arikawa/v3/voice.(*Session).JoinChannel()
      C:/Users/jason/go/pkg/mod/github.com/diamondburned/arikawa/[email protected]/voice/session.go:167 +0x144
  main.NewBot.func1()
      K:/Douki/tmpphone/bot.go:62 +0x87

Goroutine 31 (running) created at:
  main.NewBot()
      K:/Douki/tmpphone/bot.go:61 +0x54e
  main.main()
      K:/Douki/tmpphone/main.go:66 +0xbcc
==================
2021/07/06 00:34:29 Gateway error: websocket: close sent
panic: failed to start gateway: first error: WS error: websocket: close 4003: Not authenticated.

goroutine 1 [running]:
main.main()
        K:/Douki/tmpphone/main.go:127 +0x18de
exit status 2