### Bug Description PSF-2.0 is not in the list of supported SPDX licenses for the Python package we are using. Rockcraft will thus wrongfully complain about it not being a valid license. ### To Reproduce use `license: PSF-2.0` in the rockfile and you'll see `License PSF-2.0 not valid. It must be valid and in SPDX format` You can confirm this by checking the Python module's list of licenses: ```python import spdx_lookup as lookup lookup.spdx.licenses() ``` ### Environment All ### rockcraft.yaml ```shell name: python base: ubuntu:20.04 version: '3.8' license: PSF-2.0 platforms: amd64: parts: foo: plugin: nil ``` ### Relevant log output ```shell `License PSF-2.0 not valid. It must be valid and in SPDX format` ```