chore(deps): update neutron digest to b9e3818 (#960)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
diff --git a/images/neutron/Earthfile b/images/neutron/Earthfile
index 65f1238..bfff1e2 100644
--- a/images/neutron/Earthfile
+++ b/images/neutron/Earthfile
@@ -2,7 +2,7 @@
 
 ARG --global PROJECT=neutron
 ARG --global RELEASE=zed
-ARG --global PROJECT_REF=f83e1fd4f057578e1a0b30edae3cc3161f28f5e9
+ARG --global PROJECT_REF=b9e3818b6e8905f5717d9888014f7e42141aacf0
 
 build:
   FROM ../openstack-service+builder --RELEASE=${RELEASE}