sandbox: change from n1 to e2 instances

This conforms with a policy change, and should save money with no
measurable performance impact.

Removes bradfitz's SSH key from instances (that are inaccessible
anyway).

Updates golang/go#25224

Change-Id: I1733192c98deee1deabf2237ae5fe19edd29ab93
Reviewed-on: https://go-review.googlesource.com/c/playground/+/229957
Run-TryBot: Alexander Rakoczy <alex@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Carlos Amedee <carlos@golang.org>

Author: toothrot

sandbox/sandbox.tf

@@ -36,9 +36,8 @@ data "google_compute_image" "cos" {
 
 resource "google_compute_instance_template" "inst_tmpl" {
   name_prefix  = "play-sandbox-tmpl"
-  machine_type = "n1-standard-8"
+  machine_type = "e2-standard-8"
   metadata     = {
-    "ssh-keys"                  = "bradfitz:ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDaRpEbckQ+harGnrKUjk3JziwYqvz2bRNn0ngpzROaeCwm1XetDby/fgmQruZE/OBpbeOaCOd/yyP89Oer9CJx41AFEfHbudePZti/y+fmZ05N+QoBSAG0JtYWVydIjAjCenKBbNrYmwcQ840uNdIv9Ztqu3lbO/syMgcajappzdqMlwVZuHTJUe1JQD355PiinFHPTa7l0MrZPfiSsBdiTGmO39iVa312yshu6dZAvDgRL+bgIzTL6udPL/cVq+zlkvoZbzC4ajuZs4w2in+kqXHQSxbKHlXOhPrej1fwhspm+0Y7hEZOaN5Juc5GseNCHImtJh1rei1Qa4U/nTjt bradfitz@bradfitz-dev"
     "gce-container-declaration" = data.local_file.konlet.content
     "user-data"                 = data.local_file.cloud_init.content
   }