Version update workflow removed

[ihsaan-ullah]

@Didayolo @ObadaS

Description

This PR removes the version update workflow. From now on before releasing a new version we will following the steps below (to be added to wiki at a suitable place)

Steps for new releases

1. Create a PR and update the version.json to the intended version(e.g. if current version is 1.18.0, then the new releases will be 1.19.0). Example below

{
  "tag_name": "1.19.0",
  "release_name": "1.19.0",
  "published_at": "2025-05-12T15:54:30Z",
  "html_url": "https://github.com/codalab/codabench/releases/tag/1.19.0"
}

2. Merge the PR into develop and then into master
3. Create a new release with the new release info 1.19.0
4. Deploy master branch on production

A checklist for hand testing

• I have tested the manual version updates on a test repository and it works well.
• To test if the release created is ok, we should check the version number and link on codabench website and also download the release zip and check if version.json has correct information when matched with the latest release

Checklist

• Code review by me
• Hand tested by me
• I'm proud of my work
• Code review by reviewer
• Hand tested by reviewer
• CircleCi tests are passing
• Ready to merge