package/libubox: bump version to 3868f47

Changelog:

 - 3868f47 blob: constify attr argument to blob_memdup
 - eb9bcb6 ustream: prevent recursive calls to the read callback
 - 12bda4b CI: add CodeQL workflow tests
 - a2fce00 CI: add build test run
 - c1be505 udebug: fix crash in udebug_entry_vprintf with longer strings
 - 6339204 CMakeLists.txt: bump minimum cmake version
 - ca3f6d0 udebug: fix file descriptor initialization for __udebug_buf_map
 - df5b714 udebug: add mips specific quirk
 - d27acfe udebug: add more checks for uninitialized buffers
 - 40acbe3 udebug: wait for response after buffer add/remove
 - e84c000 udebug: add inline helper function to test if a buffer is allocated
 - 325fea5 udebug: add functions for manipulating entry length
 - e80dc00 link librt if needed for shm_open
 - 260ad5b udebug: add ulog support
 - b77f2a4 uloop: fix build using C++ compilers
 - d4c3066 udebug: add udebug library code
 - b3fa3d9 uloop: reset flags after __uloop_fd_delete call
 - 8a5a431 uloop: fix typo in signal handling rework
 - f7d1569 uloop: properly initialize signal handler mask
 - 13d9b04 uloop: add support for user defined signal handlers
 - 82fa648 uloop: add support for interval timers

Signed-off-by: Lance Fredrickson <lancethepants@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/libubox/libubox.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256  918acc85199117ef109f2a204020f6fe4d5a1724a09888f45b70b6474345d6fe  libubox-75a3b870cace1171faf57bd55e5a9a2f1564f757-git4.tar.gz
+sha256  df6e1350fd11016ef30242a279cec195d91e6748c11c40e0991593718c46fa52  libubox-3868f47c8f6c6570e62a3cdf8a7f26ffb1a67e6a-git4.tar.gz

package/libubox/libubox.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-LIBUBOX_VERSION = 75a3b870cace1171faf57bd55e5a9a2f1564f757
+LIBUBOX_VERSION = 3868f47c8f6c6570e62a3cdf8a7f26ffb1a67e6a
 LIBUBOX_SITE = https://git.openwrt.org/project/libubox.git
 LIBUBOX_SITE_METHOD = git
 LIBUBOX_LICENSE = ISC, BSD-3-Clause