tailcfg: move LogHeapPprof from Debug to c2n [capver 69]

And delete Debug.GoroutineDumpURL, which was already in c2n.

Updates #8923

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

ipn/ipnlocal/c2n_pprof.go

@@ -0,0 +1,17 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !js && !wasm
+
+package ipnlocal
+
+import (
+	"net/http"
+	"runtime/pprof"
+)
+
+func init() {
+	c2nLogHeap = func(w http.ResponseWriter, r *http.Request) {
+		pprof.WriteHeapProfile(w)
+	}
+}