package/git: security bump to version 2.31.8

Fix three CVEs (CVE-2023-25652, CVE-2023-25815, and CVE-2023-29007).
For details on these, see release announcement:

https://lore.kernel.org/git/xmqqa5yv3n93.fsf@gitster.g/

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/git/git.hash

@@ -1,5 +1,5 @@
 # From: https://www.kernel.org/pub/software/scm/git/sha256sums.asc
-sha256  30674629605a12d3ef4f9c752d5561862f04a48952b1799b9815f9884e4e0f6d  git-2.31.7.tar.xz
+sha256  c7a0c77fa63de669494b10a6b2a7f85d1e9ba69add501c89e035a36ded14d1d5  git-2.31.8.tar.xz
 # Locally calculated
 sha256  5b2198d1645f767585e8a88ac0499b04472164c0d2da22e75ecf97ef443ab32e  COPYING
 sha256  1922f45d2c49e390032c9c0ba6d7cac904087f7cec51af30c2b2ad022ce0e76a  LGPL-2.1

package/git/git.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-GIT_VERSION = 2.31.7
+GIT_VERSION = 2.31.8
 GIT_SOURCE = git-$(GIT_VERSION).tar.xz
 GIT_SITE = $(BR2_KERNEL_MIRROR)/software/scm/git
 GIT_LICENSE = GPL-2.0, LGPL-2.1+