internal/debug: remove memsize (#30253)

Removing because memsize will very likely be broken by Go 1.23. See
fjl/memsize#4

go.mod

@@ -25,7 +25,6 @@ require (
 	github.com/fatih/color v1.13.0
 	github.com/ferranbt/fastssz v0.1.2
 	github.com/fjl/gencodec v0.0.0-20230517082657-f9840df7b83e
-	github.com/fjl/memsize v0.0.2
 	github.com/fsnotify/fsnotify v1.6.0
 	github.com/gammazero/deque v0.2.1
 	github.com/gballet/go-libpcsclite v0.0.0-20190607065134-2772fd86a8ff

internal/debug/flags.go

@@ -31,15 +31,12 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/metrics/exp"
-	"github.com/fjl/memsize/memsizeui"
 	"github.com/mattn/go-colorable"
 	"github.com/mattn/go-isatty"
 	"github.com/urfave/cli/v2"
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
-var Memsize memsizeui.Handler
-
 var (
 	verbosityFlag = &cli.IntFlag{
 		Name:     "verbosity",
@@ -315,7 +312,6 @@ func StartPProf(address string, withMetrics bool) {
 	if withMetrics {
 		exp.Exp(metrics.DefaultRegistry)
 	}
-	http.Handle("/memsize/", http.StripPrefix("/memsize", &Memsize))
 	log.Info("Starting pprof server", "addr", fmt.Sprintf("http://%s/debug/pprof", address))
 	go func() {
 		if err := http.ListenAndServe(address, nil); err != nil {