chore(deps): update keystone digest to 5a55e9d (#959)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
diff --git a/images/keystone/Earthfile b/images/keystone/Earthfile
index 4c5c706..580ef5d 100644
--- a/images/keystone/Earthfile
+++ b/images/keystone/Earthfile
@@ -2,7 +2,7 @@
 
 ARG --global RELEASE=2023.2
 ARG --global PROJECT=keystone
-ARG --global PROJECT_REF=7de9f7d49dd4142dccc1968028e12a3ca2b7847f
+ARG --global PROJECT_REF=5a55e9de15c7f390e43addc5f3ff1a4809ec1a5b
 
 build:
   FROM ../openstack-service+builder --RELEASE=${RELEASE}