Parse the package.json file entirely for NPM uploads

🔭 Context

When NPM packages are published to the NPM GitLab package registry, a background job is kicked. Among other things, it will collect the package.json file and parse it.

In gitlab-com/gl-infra/production#18253, we were made aware that the event based parsing that we have for NPM uploads is not working properly.

Given that the file that is parsed is already limited in size, we can fall back to a simpler implementation for parsing: simply parse the entire JSON document (and load it in memory).

🤔 What does this MR do and why?

• Switch NPM package.json parsing from oj saj parsing to Gitlab::Json.parse.
• Update the related specs

🏎 MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

✅

🌈 Screenshots or screen recordings

🤷 (No GitLab UI changes)

⚙ How to set up and validate locally

• Have a project and a PAT ready.
• Create a folder with:
  1. package.json :

     {
       "name": "@scope/subkeys",
       "version": "1.0.0",
       "description": "",
       "main": "index.js",
       "subkeys": {
         "name": "nop",
         "version": "nop"
       },
       "scripts": {
         "test": "echo \"Error: no test specified\" && exit 1"
       },
       "author": "",
       "license": "ISC"
     }

  2. .npmrc (replace <pat> and <project_id>):

  @scope:registry=http://gdk.test:8000/api/v4/projects/<project_id>/packages/npm/
  //gdk.test:8000/api/v4/projects/<project_id>/packages/npm/:_authToken="<PAT>"

• run $ npm publish

On master: this fails with

💥

With this MR, the upload succeeds 🎉