New license request: Unlicense-variant [SPDX-Online-Tools]

[xsuchy]

1. License Name: Unlicense variant
2. Short identifier: Unlicense-variant
3. License Author or steward: Unknown
4. Comments: This was found during License review in Fedora Linux https://gitlab.com/fedora/legal/fedora-license-data/-/issues/581 and it it used in a package libwhirpool
5. License Request Url: http://tools.spdx.org/app/license_requests/399
6. URL(s): https://github.com/dfateyev/libwhirlpool/blob/master/README#L27
7. OSI Status: Unknown
8. Example Projects: https://github.com/dfateyev/libwhirlpool

[xsuchy]

The license text:

This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any means.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

Note that this may be related to #2583 that is similar.