update libwebm to libwebm-1.0.0.31-10-g3b63004

This fixes a build error seen in gcc 15:
3b63004 mkvparser/mkvparser.cc: add missing <cstdint> include

Bug: aomedia:357622679
Change-Id: I6c4a1795d189f9993d4f2c5c9f0375912bc58f0c
(cherry picked from commit e448dcd13a9f534c7291903e9ab18dfc4fea54ad)

third_party/libwebm/README.libaom

diff --git a/third_party/libwebm/README.libaom b/third_party/libwebm/README.libaom
index a038418..6e43487 100644
--- a/third_party/libwebm/README.libaom
+++ b/third_party/libwebm/README.libaom
@@ -1,5 +1,5 @@
 URL: https://chromium.googlesource.com/webm/libwebm
-Version: f4b07ec144e61d9089144e8d54b4ecda0219c562
+Version: 3b630045052e1e4d563207ab9e3be8d137c26067
 License: BSD
 License File: LICENSE.TXT
 

third_party/libwebm/mkvmuxer/mkvmuxerutil.h

diff --git a/third_party/libwebm/mkvmuxer/mkvmuxerutil.h b/third_party/libwebm/mkvmuxer/mkvmuxerutil.h
index 3355428..85fc2a2 100644
--- a/third_party/libwebm/mkvmuxer/mkvmuxerutil.h
+++ b/third_party/libwebm/mkvmuxer/mkvmuxerutil.h
@@ -8,9 +8,9 @@
 #ifndef MKVMUXER_MKVMUXERUTIL_H_
 #define MKVMUXER_MKVMUXERUTIL_H_
 
-#include "mkvmuxertypes.h"
+#include <stdint.h>
 
-#include "stdint.h"
+#include "mkvmuxertypes.h"
 
 namespace mkvmuxer {
 class Cluster;

third_party/libwebm/mkvparser/mkvparser.cc

diff --git a/third_party/libwebm/mkvparser/mkvparser.cc b/third_party/libwebm/mkvparser/mkvparser.cc
index eddbc7e..042a0c5 100644
--- a/third_party/libwebm/mkvparser/mkvparser.cc
+++ b/third_party/libwebm/mkvparser/mkvparser.cc
@@ -16,6 +16,7 @@
 #include <cfloat>
 #include <climits>
 #include <cmath>
+#include <cstdint>
 #include <cstring>
 #include <memory>
 #include <new>