Sync with OpenBSD strptime.c.

They took two of our changes (missing consts and %v), but not the %P one.

Change-Id: Ib80de6bca54a7ae31e7530b35d40497213ce928f

libc/tzcode/strptime.c

diff --git a/libc/tzcode/strptime.c b/libc/tzcode/strptime.c
index 20160c9..525dfc4 100644
--- a/libc/tzcode/strptime.c
+++ b/libc/tzcode/strptime.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: strptime.c,v 1.31 2023/03/02 16:21:51 millert Exp $ */
+/*	$OpenBSD: strptime.c,v 1.33 2025/08/26 22:30:42 millert Exp $ */
 /*	$NetBSD: strptime.c,v 1.12 1998/01/20 21:39:40 mycroft Exp $	*/
 /*-
  * Copyright (c) 1997, 1998, 2005, 2008 The NetBSD Foundation, Inc.
@@ -68,8 +68,8 @@
 #define FIELD_TM_YDAY	(1 << 3)
 #define FIELD_TM_YEAR	(1 << 4)
 
-static const char gmt[] = { "GMT" };
-static const char utc[] = { "UTC" };
+static char const gmt[] = { "GMT" };
+static char const utc[] = { "UTC" };
 /* RFC-822/RFC-2822 */
 static const char * const nast[5] = {
        "EST",    "CST",    "MST",    "PST",    "\0\0\0"
@@ -194,7 +194,7 @@
 				return (NULL);
 			break;
 
-		case 'v':	/* Android: the date as "%e-%b-%Y" for strftime() compat; glibc does this too. */
+		case 'v':	/* The date as "%e-%b-%Y". */
 			_LEGAL_ALT(0);
 			if (!(bp = _strptime(bp, "%e-%b-%Y", tm, 0)))
 				return (NULL);