Update ghcr.io/medizininformatik-initiative/flare Docker tag to v2.6.0

Author: renovate[bot]

.github/integration-test/docker-compose.yml

@@ -115,7 +115,7 @@ services:
       - "blaze-data:/app/data"
 
   flare:
-    image: ghcr.io/medizininformatik-initiative/flare:2.5.0
+    image: ghcr.io/medizininformatik-initiative/flare:2.6.0
     ports:
       - "8092:8080"
     environment: