chore(deps): update yuzutech/kroki-mermaid docker tag to v0.28.0

Author: renovate[bot]

150_gitlab/135_integrations/compose.yml

@@ -14,7 +14,7 @@ services:
     image: yuzutech/kroki-blockdiag:0.21.3
 
   mermaid:
-    image: yuzutech/kroki-mermaid:0.27.0
+    image: yuzutech/kroki-mermaid:0.28.0
 
   bpmn:
     image: yuzutech/kroki-bpmn:0.27.0