scriptcheck.yml: added Python 3.4

[firewave]

See #3596 (comment)

[firewave]

No Python 3.4 available within the CI.

Version 3.4.10 was not found in the local cache
Error: Version 3.4.10 with arch x64 not found
The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json

[
{
    "version": "3.4.10",
    "stable": true,
    "release_url": "https://github.com/actions/python-versions/releases/tag/3.4.10",
    "files": [
      {
        "filename": "python-3.4.10-linux-18.04-x64.tar.gz",
        "arch": "x64",
        "platform": "linux",
        "platform_version": "18.04",
        "download_url": "https://github.com/actions/python-versions/releases/download/3.4.10/python-3.4.10-linux-18.04-x64.tar.gz"
      }
    ]
  },
  {
    "version": "3.4.4",
    "stable": true,
    "release_url": "https://github.com/actions/python-versions/releases/tag/3.4.4-88098",
    "files": [
      {
        "filename": "python-3.4.4-win32-x64.zip",
        "arch": "x64",
        "platform": "win32",
        "download_url": "https://github.com/actions/python-versions/releases/download/3.4.4-88098/python-3.4.4-win32-x64.zip"
      },
      {
        "filename": "python-3.4.4-win32-x86.zip",
        "arch": "x86",
        "platform": "win32",
        "download_url": "https://github.com/actions/python-versions/releases/download/3.4.4-88098/python-3.4.4-win32-x86.zip"
      }
    ]
  }
]

[firewave]

Will partially implicitly tested by using the platform 3.4 version on Ubuntu 14.04 (if keep this within the CI/supported platforms).