Update dependabot.yml

I forgot that dependabot just does yarn with the npm ecosystem. Removing the yarn section

Author: St0rmz1

.github/dependabot.yml

@@ -6,12 +6,6 @@ updates:
     schedule:
       interval: "weekly"
 
-  # Update Yarn dependencies based on yarn.lock
-  - package-ecosystem: "yarn"
-    directory: "/" # Root directory
-    schedule:
-      interval: "weekly"
-
   # Keep Dependabot itself up to date
   - package-ecosystem: "github-actions"
     directory: "/" # Root directory (or specify if actions are elsewhere)