Ports/ffmpeg: Update to version 6.0

This additionally includes a patch from the current master branch,
which fixes building with binutils 2.41 and newer.

Ports/ffmpeg/patches/0002-Adapt-to-the-Serenity-thread-name-interface.patch

@@ -0,0 +1,31 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Tim Schumacher <timschumi@gmx.de>
+Date: Mon, 2 Oct 2023 01:17:46 +0200
+Subject: [PATCH] Adapt to the Serenity thread name interface
+
+---
+ libavutil/thread.h | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/libavutil/thread.h b/libavutil/thread.h
+index 2f5e7e1cb552fd12f954334e80960cbfb6ac7108..264d6ae646dc78e0f21b58445a412487e055ebc5 100644
+--- a/libavutil/thread.h
++++ b/libavutil/thread.h
+@@ -26,6 +26,8 @@
+ 
+ #if HAVE_PRCTL
+ #include <sys/prctl.h>
++#include <unistd.h>
++#include <string.h>
+ #endif
+ 
+ #include "error.h"
+@@ -195,7 +197,7 @@ static inline int ff_thread_once(char *control, void (*routine)(void))
+ static inline int ff_thread_setname(const char *name)
+ {
+ #if HAVE_PRCTL
+-    return AVERROR(prctl(PR_SET_NAME, name));
++    return AVERROR(prctl(PR_SET_THREAD_NAME, gettid(), name, strlen(name)));
+ #endif
+ 
+     return AVERROR(ENOSYS);