licenses: Mark unclear GPL licenses explicitly deprecated

We recently switched to more explicit GPL license names in line
with the SPDX change and GNU Foundation recommendations:
https://www.gnu.org/licenses/identify-licenses-clearly.html

This followed up older change to use the recommended SPDX ID
https://github.com/NixOS/nixpkgs/commit/18a5e8c36b2681f5fc4aecd79f4cc723365d2d94
but using the `-only` variant for these deprecated licenses too
makes it harder to check for them automatically.

Let’s switch to the appropriate SPDX ID again.

0 files changed, 0 insertions, 0 deletions