all: update golang.zx2c4.com/wireguard to github.com/tailscale/wireguard-go (#6692)

This is temporary while we work to upstream performance work in
https://github.com/WireGuard/wireguard-go/pull/64. A replace directive
is less ideal as it breaks dependent code without duplication of the
directive.

Signed-off-by: Jordan Whited <jordan@tailscale.com>

types/tkatype/tkatype_test.go

@@ -5,8 +5,9 @@
 package tkatype
 
 import (
-	"golang.org/x/crypto/blake2s"
 	"testing"
+
+	"golang.org/x/crypto/blake2s"
 )
 
 func TestSigHashSize(t *testing.T) {