Disable dependabot in favour of renovate

.github/dependabot.yml

@@ -1,40 +0,0 @@
-version: 2
-updates:
-  - package-ecosystem: "bundler"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-      timezone: "Europe/Helsinki"
-    groups:
-      bundler:
-        patterns:
-          - "*"
-
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-      timezone: "Europe/Helsinki"
-    groups:
-      github-actions:
-        patterns:
-          - "*"
-
-  - package-ecosystem: "gitsubmodule"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-      timezone: "Europe/Helsinki"
-    groups:
-      gitsubmodule:
-        patterns:
-          - "*"
-
-  - package-ecosystem: "npm"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-    groups:
-      npm:
-        patterns:
-          - "*"