Devenv: Update Graphite port in dev datasources (#17255)

devenv/datasources.yaml

+
 apiVersion: 1
 
 datasources:
   - name: gdev-graphite
     type: graphite
     access: proxy
-    url: http://localhost:8080
+    url: http://localhost:8180
     jsonData:
       graphiteVersion: "1.1"