Tune Dependabot (#4775)

Switch mvn to development deps only. This should cover mvn plugins.

Signed-off-by: Holger Friedrich <[email protected]>

Author: holgerfriedrich

.github/dependabot.yml

@@ -17,5 +17,6 @@ updates:
     schedule:
       interval: "weekly"
     open-pull-requests-limit: 10
-    labels:
-      - dependencies
+    labels: [ ]
+    allow:
+      - dependency-type: "development"