Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 7b4f759047e6b0c22c4e2d9920c6aaff3eb6f896
  - Prepare Xtesting 2024.1

    Change-Id: I457cd8a5a51db6b3095df95d2aca6cdc22b0774b
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index defed6f..7b4f759 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit defed6fbb50cc753daac1e586c4809c85dce7f4d
+Subproject commit 7b4f759047e6b0c22c4e2d9920c6aaff3eb6f896