remove script for adding/removing heroku dynos (#6234)

Author: chris48s

Procfile

@@ -1,5 +1 @@
 web: npm run start:server:prod
-scale4: npm run heroku:scale 4
-scale5: npm run heroku:scale 5
-scale6: npm run heroku:scale 6
-scale7: npm run heroku:scale 7

package-lock.json

@@ -39,7 +39,6 @@
     "glob": "^7.1.6",
     "graphql": "^14.7.0",
     "graphql-tag": "^2.11.0",
-    "heroku-client": "^3.1.0",
     "ioredis": "4.23.0",
     "joi": "17.4.0",
     "joi-extension-semver": "5.0.0",
@@ -101,7 +100,6 @@
     "defs": "node scripts/export-service-definitions-cli.js > service-definitions.yml",
     "build": "run-s defs features && gatsby build",
     "heroku-postbuild": "run-s --silent build",
-    "heroku:scale": "node scripts/heroku-scale.js",
     "start:server:prod": "node server",
     "now-start": "npm run start:server:prod",
     "start:server:e2e-on-build": "node server 8080",