fix: invalid details in dependabot.yml

The property '#/updates/0/package-ecosystem' value "pnpm" did not match one of the following values: npm, bundler, composer, devcontainers, maven, mix, cargo, gradle, nuget, gomod, docker, elm, gitsubmodule, github-actions, pip, terraform, pub, swift

.github/dependabot.yml

@@ -5,7 +5,7 @@
 
 version: 2
 updates:
-  - package-ecosystem: "pnpm" # See documentation for possible values
+  - package-ecosystem: "npm" # See documentation for possible values
     directory: "/" # Location of package manifests
     schedule:
       interval: "weekly"