[Yoga] Release neutron

This is a convenience release before moving Yoga to extended maintenance
(estimated 2023-11-02).

$ git log --oneline --no-merges 20.3.1..d0c54786f
d55b30844f Fix ACL sync when default sg group is created
052c3899cb [OVN][L3] Optimize FIP update operation
6af9f70e0b Set result when lswitch port exist
61d9e5972d Ensure traffic is not centralized if DVR is enabled
4f043fb7ad Don't allow deletion of the router ports without IP addresses
78b7cf82dd Delete sg rule which remote is the deleted sg
3e6b2b77b2 [OVN] Expose chassis hosting information in LSP
226e29af1a Load FIP information during initialize not init
3785eac7a5 [OVN] Hash Ring: Set nodes as offline upon exit
73ba302faf [OVN] Improve Hash Ring logs
4764ed550a [qos] _validate_create_network_callback return in no network
cd4f345f60 [OVN][Trunk] Add port binding info on subport when parent is bound
5ae479c7e3 Delete the "Chassis_Private" register when deleting an agent
3328be0994 Return 409 Conflict to tenant user deleting port attached to FIP
ba16962d34 [OVN] Remove SB "Chassis"/"Chassis_Private" duplicated registers
d541ee9731 Make DB migration creating indexes in RBACs conditional
70a7188209 [OVN][Migration] Enable settings backup subnet for NFS clients
b6145ee13e Handle no more IP addresses available during a network sync

Change-Id: Iaf0b24b7383dc461d28cd1acd101428da8c0f3a2
Signed-off-by: Hervé Beraud <hberaud@redhat.com>

deliverables/yoga/neutron.yaml

@@ -46,6 +46,10 @@ releases:
     projects:
       - repo: openstack/neutron
         hash: 5c4f9023cfe13c1e3e07e28cde35366bdb2ce0e0
+  - version: 20.4.0
+    projects:
+      - repo: openstack/neutron
+        hash: d0c54786fae5a7464f477364dcd4b154e6672c0e
 branches:
   - name: stable/yoga
     location: 20.0.0.0rc1