release 2.2.3 (#4062)

* chore: create release 2.2.3

* fix: update keycloak-theme to 4.1.8 (#4063)

---------

Co-authored-by: Flora Thiebaut <flora.thiebaut@sdsc.ethz.ch>

Author: RenkuBot

helm-chart/renku/values.yaml

@@ -318,7 +318,7 @@ keycloakx:
     enabled: false
   extraInitContainers: |
     - name: theme-provider
-      image: renku/keycloak-theme:4.1.7
+      image: renku/keycloak-theme:4.1.8
       imagePullPolicy: IfNotPresent
       command:
         - sh