media-video/gpac: fix build with ffmpeg 6

ffmpeg 7 is fine (w/ patch), but 2.4.0 included a 6 regression.

Closes: https://bugs.gentoo.org/951622
Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

media-video/gpac/files/gpac-2.4.0-ffmpeg6.patch

@@ -0,0 +1,11 @@
+https://bugs.gentoo.org/951622
+https://github.com/gpac/gpac/commit/8d7cac0bf9f9775cae1d43de7138206758f28b0c
+--- a/src/filters/ff_mx.c
++++ b/src/filters/ff_mx.c
+@@ -248,5 +248,5 @@
+ 
+ 
+-#if (LIBAVFORMAT_VERSION_MAJOR <= 59)
++#if (LIBAVFORMAT_VERSION_MAJOR < 61)
+ static int ffavio_write_packet(void *opaque, uint8_t *buf, int buf_size)
+ #else

media-video/gpac/gpac-2.4.0.ebuild

@@ -63,6 +63,7 @@ BDEPEND="
 
 PATCHES=(
 	"${FILESDIR}"/${P}-configure-stddef.patch
+	"${FILESDIR}"/${P}-ffmpeg6.patch
 	"${FILESDIR}"/${P}-ffmpeg7.patch
 )