Consider using `/` in category separator for Code Scanning supported sub-categories

[felickz]

Currently project: category is recognized but without a value.

• Thinking here, the ; could be replaced with a / (but this would be a breaking change)

Current sample API result gh api /repos/advanced-security/sample-javascript-monorepo/code-scanning/analyses?ref=refs/pull/15/merge

  {
    "ref": "refs/pull/15/merge",
    "commit_sha": "fb990ba8f764ac298da9f0de5a92dd82ff516b1d",
    "analysis_key": "(default)",
    "environment": "{}",
    "category": "/language:javascript-typescript;project:babel-plugin-transform-react-jsx-self",
    "error": "",
    "created_at": "2025-04-15T02:12:41Z",
    "results_count": 0,
    "rules_count": 105,
    "id": 452242247,
    "url": "https://api.github.com/repos/advanced-security/sample-javascript-monorepo/code-scanning/analyses/452242247",
    "sarif_id": "1bff13b8-199f-11f0-8f1f-931d3d8871db",
    "tool": {
      "name": "CodeQL",
      "guid": null,
      "version": "2.21.0"
    },
    "deletable": true,
    "warning": ""
  }

With / :

• TODO Document

[aegilops]

Let's go ahead and do this, and bump the version up to a new major version in the tag.

We can add a flag to go with the old approach for folk already using the Action.