wasm: drop pprof dependency

We can use the browser tools to profile, pprof adds 200K to the binary size.

Updates #3157

Signed-off-by: Mihai Parparita <mihai@tailscale.com>

log/logheap/logheap.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build !js
+// +build !js
+
 // Package logheap logs a heap pprof profile.
 package logheap
 

log/logheap/logheap_js.go

@@ -0,0 +1,8 @@
+// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package logheap
+
+func LogHeap(postURL string) {
+}