manifest: Update EDTT to latest version

Update the EDTT module to:
b9ca3c7030518f07b7937dacf970d37a47865a76

Including the following:
* b9ca3c7 Fix for for python >= 3.11
* fe9b1d1 Corrected ISO interval for LL/CIS/PER/BV-05-C

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
(cherry picked from commit 59685b51)