chore(deps): update quay.io/keycloak/keycloak docker tag to v26.2.5

Author: renovate[bot]

stack/docker-compose.yml

@@ -42,7 +42,7 @@ services:
     entrypoint: /bin/sh -c "chmod 600 /pgadmin4/pgpass; /entrypoint.sh;" # see https://www.postgresql.org/docs/current/libpq-pgpass.html#LIBPQ-PGPASS (last paragraph)
 
   keycloak:
-    image: quay.io/keycloak/keycloak:26.1.5@sha256:be6a86215213145bfb4fb3e2b3ab982a806d00262655abdcf3ffa6a38d241c7c
+    image: quay.io/keycloak/keycloak:26.2.5@sha256:4883630ef9db14031cde3e60700c9a9a8eaf1b5c24db1589d6a2d43de38ba2a9
     command:
       - start-dev
     environment: