And if you want something OSI-approved you can use either the MIT-0 [1] or the Zero-Clause BSD [2] license. The MIT-0 license is the MIT license without the attribution requirement, the Zero-Clause BSD license is (somewhat misleadingly) the ISC license without the attribution requirement.

[1] https://opensource.org/licenses/MIT-0

[2] https://opensource.org/licenses/0BSD