Fix for the hardlink problem

[AlexDenisov]

Fixes #1.

I tested it using my account, the following setup works just fine:

{
  "name": "test",
  "image": "ubuntu",
  "features": {
    "ghcr.io/alexdenisov/features/feature-cmake": {}
  }
}

[evelinabis]

Good pr. Using "ghcr.io/devcontainers-community/features/cmake:2.0.1": {} isn't working, but as suggested ("ghcr.io/alexdenisov/features/feature-cmake": {}) all is ok. Approved