poetry: Duplicated artifacts in cache

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: Linux Ubuntu 20.04
• Poetry version: 1.1.13

Issue

Poetry was able somehow to create multiple same name entries in the cache:

~/.cache/pypoetry/artifacts$ find . -name forma*
./f7/4a/92/77326137086392f59eb66c784e369a6ab387f4178c4b950abe48ed5c4c/formasaurus-0.9.0+ds.3-py2.py3-none-any.whl
./e5/21/35/b92d6ab0cf36e72fc6a56d5ae502caf69b52f953a671d9e196cb1b4abd/formasaurus-0.9.0+ds.2-py2.py3-none-any.whl
./c4/38/b9/6d7ce39991c8319ed8ac62765317620a34d76f60f30152ca89e85d298b/formasaurus-0.9.0+ds.2-py2.py3-none-any.whl
./d9/25/49/b44cc41365aeb2139a3a5a87d530560a01faf827479ed1cffbcb6c2e0b/formasaurus-0.9.0+ds.3-py2.py3-none-any.whl

This will likely generate broken poetry.lock files since the collected artifact (by name) is no longer deterministic.