tsweb: don't hook up pprof handlers in javascript builds

Updates #15160

Signed-off-by: David Anderson <dave@tailscale.com>

tsweb/pprof_js.go

@@ -0,0 +1,8 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package tsweb
+
+func addProfilingHandlers(d *DebugHandler) {
+	// No pprof in js builds, pprof doesn't work and bloats the build.
+}