CLOUDP-286235: Update dependabot to cover package.json in root (#291)

Author: lovisaberggren

.github/dependabot.yml

@@ -20,7 +20,7 @@ updates:
     reviewers:
       - "mongodb/apix-2"
   - package-ecosystem: npm
-    directory: "/tools/postman"
+    directory: "/"
     schedule:
       interval: weekly
       day: tuesday