Switch to Antelope images (#1227)

diff --git a/images/ironic/Dockerfile b/images/ironic/Dockerfile
index a006e08..9a0016e 100644
--- a/images/ironic/Dockerfile
+++ b/images/ironic/Dockerfile
@@ -15,7 +15,7 @@
 ARG RELEASE
 
 FROM registry.atmosphere.dev/library/openstack-venv-builder:${RELEASE} AS build
-ARG IRONIC_GIT_REF=22aa29b864eecd00bfb7c67cc2075030da1eb1d0
+ARG IRONIC_GIT_REF=c51cf2859140884150422f423d2e91119972eaac
 ADD --keep-git-dir=true https://opendev.org/openstack/ironic.git#${IRONIC_GIT_REF} /src/ironic
 RUN git -C /src/ironic fetch --unshallow
 RUN --mount=type=cache,mode=0755,target=/root/.cache/pip,sharing=private <<EOF bash -xe