chore: update build to use cjs format

Signed-off-by: Rogerio Angeliski <angeliski@hotmail.com>

.changeset/metal-timers-shout.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend-module-rails': minor
+---
+
+update publish format from ESM to CJS

plugins/scaffolder-backend-module-rails/package.json

@@ -8,12 +8,12 @@
   "private": false,
   "publishConfig": {
     "access": "public",
-    "main": "dist/index.esm.js",
+    "main": "dist/index.cjs.js",
     "types": "dist/index.d.ts"
   },
   "scripts": {
-    "build": "backstage-cli plugin:build",
-    "start": "backstage-cli plugin:serve",
+    "build": "backstage-cli backend:build",
+    "start": "backstage-cli backend:dev",
     "lint": "backstage-cli lint",
     "test": "backstage-cli test",
     "prepack": "backstage-cli prepack",