dependabot: stop dashboard npm upgrade PRs

Signed-off-by: Ernesto Puerta <[email protected]>

Author: epuertat

.github/dependabot.yml

@@ -1,17 +1,6 @@
 ---
 version: 2
 updates:
-  - package-ecosystem: "npm"
-    directory: "/src/pybind/mgr/dashboard/frontend"
-    schedule:
-      interval: "daily"
-    commit-message:
-      prefix: "mgr/dashboard:"
-    labels:
-      - "dashboard"
-    pull-request-branch-name:
-      separator: "-"
-
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule: