Update to git version v2.31.0, this requires changes for these
upstream commits:
* 36a317929b8f0c67d77d54235f2d20751c576cbb
refs: switch peel_ref() to peel_iterated_oid()
Signed-off-by: Christian Hesse <mail@eworm.de>
Change-Id: Idb3abf22eb68ba5219f22075811884bbce786c3b