chore: remove dependabot config

Removed in favor of security updates only.

.github/dependabot.yml

@@ -1,19 +0,0 @@
-# To get started with Dependabot version updates, you'll need to specify which
-# package ecosystems to update and where the package manifests are located.
-# Please see the documentation for all configuration options:
-# https://help.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
-
-version: 2
-updates:
-  - package-ecosystem: "npm"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-      day: "monday"
-      time: "09:00"
-      timezone: "Europe/Berlin"
-    reviewers: # Automatically assign reviewer
-      - "bpmn-io/modeling-dev"
-    commit-message:
-      prefix: "chore:"
-    versioning-strategy: "increase-if-necessary"