all: use any instead of interface{}

My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

wgengine/magicsock/magicsock.go

@@ -1197,7 +1197,7 @@ var errDropDerpPacket = errors.New("too many DERP packets queued; dropping")
 var errNoUDP = errors.New("no UDP available on platform")
 
 var udpAddrPool = &sync.Pool{
-	New: func() interface{} { return new(net.UDPAddr) },
+	New: func() any { return new(net.UDPAddr) },
 }
 
 // sendUDP sends UDP packet b to ipp.

wgengine/magicsock/magicsock_test.go

@@ -543,7 +543,7 @@ func makeNestable(t *testing.T) (logf logger.Logf, setT func(t *testing.T)) {
 		mu.Unlock()
 	}
 
-	logf = func(s string, args ...interface{}) {
+	logf = func(s string, args ...any) {
 		mu.RLock()
 		t := cur
 
@@ -922,7 +922,7 @@ func testActiveDiscovery(t *testing.T, d *devices) {
 	setT(t)
 
 	start := time.Now()
-	wlogf := func(msg string, args ...interface{}) {
+	wlogf := func(msg string, args ...any) {
 		t.Helper()
 		msg = fmt.Sprintf("%s: %s", time.Since(start).Truncate(time.Microsecond), msg)
 		tlogf(msg, args...)