Fix metadata (fix root test)

[andreas-hilti]

Fix the metadata component by fixing the test for the root component.

Closes: https://github.com/CycloneDX/cyclonedx-conan/issues/101

This is only an issue when used for conanfile.py (rather than conanfile.txt).

[andreas-hilti]

For the conanfile.py from https://github.com/CycloneDX/cyclonedx-conan/issues/101, it produces the following SBOM:

{
  "bomFormat": "CycloneDX",
  "specVersion": "1.3",
  "serialNumber": "urn:uuid:92a2a7ad-2470-4d04-9e3c-def967bfc4e3",
  "version": 1,
  "metadata": {
    "component": {
      "bom-ref": "[email protected]",
      "type": "application",
      "name": "conan-test",
      "version": "1.0.0"
    }
  },
  "components": [
    {
      "bom-ref": "pkg:conan/[email protected]?repository_url=https://center.conan.io",
      "type": "library",
      "name": "fmt",
      "version": "8.0.0",
      "purl": "pkg:conan/[email protected]?repository_url=https://center.conan.io"
    }
  ],
  "dependencies": [
    {
      "ref": "pkg:conan/[email protected]?repository_url=https://center.conan.io",
      "dependsOn": []
    },
    {
      "ref": "[email protected]",
      "dependsOn": [
        "pkg:conan/[email protected]?repository_url=https://center.conan.io"
      ]
    }
  ]
}