Update dependabot.yml

Author: jy95

.github/dependabot.yml

@@ -13,6 +13,10 @@ updates:
       include: "scope"
     schedule:
       interval: "daily"
+    # Add specific commit message format for security updates
+    security-updates:
+      commit-message:
+        prefix: "fix"
 # Files stored in repository testsite
   - package-ecosystem: "npm"
     directory: "/testsite"