Delete Dependabot configuration (#2480)

Remove Dependabot configuration for package updates.

Author: ericholscher

.github/dependabot.yml

@@ -1,16 +1 @@
-# Set update schedule for GitHub Actions
 
-version: 2
-updates:
-  - package-ecosystem: "pip"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-  - package-ecosystem: "bundler"
-    directory: "/"
-    schedule:
-      interval: "monthly"
-  - package-ecosystem: "github-actions"
-    directory: "/"
-    schedule:
-      interval: "monthly"