cmd/tailscaled, ipn/localapi, util/eventbus: don't link in regexp when debug is omitted

Saves 442 KB. Lock it with a new min test.

Updates #12614

Change-Id: Ia7bf6f797b6cbf08ea65419ade2f359d390f8e91
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/localapi/pprof.go

@@ -1,7 +1,7 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-//go:build !ios && !android && !js
+//go:build !ios && !android && !js && !ts_omit_debug
 
 // We don't include it on mobile where we're more memory constrained and
 // there's no CLI to get at the results anyway.