Update quay.io/keycloak/keycloak Docker tag to v26.3.4

Author: renovate[bot]

docker-compose/docker-compose-keycloak.yml

@@ -2,7 +2,7 @@ version: '3.7'
 
 services:
   keycloak:
-    image: quay.io/keycloak/keycloak:26.3.1
+    image: quay.io/keycloak/keycloak:26.3.4
     command: start-dev --import-realm
     volumes:
       - ./example-keycloak:/opt/keycloak/data/import/:rw