fix: clean the poetry cache

[frostming]

The previous command doesn't clean the cache correctly. After this change, the lock time of poetry will become comparable. (9 seconds is too dramatic)

[ipmb]

Thanks @frostming !

[frostming]

Hi, do you have any idea why the site is not updated with the latest result: https://github.com/lincolnloop/python-package-manager-shootout/actions/runs/2708687120

[ipmb]

It takes an average of the last 6 runs (which run every 6 hours) so it will take a while for the results to fully change. Since they are running on shared hardware, I wanted to avoid an anomaly skewing the results too much, but maybe 6 is excessive.

[ipmb]

I dropped it down to 4 which should only include the changes here. You can see the aggregated results here: https://github.com/lincolnloop/python-package-manager-shootout/actions/runs/2712516720

It looks like poetry's slowest runs are pretty close to pdm's fastest runs which is why some individual results are very close, but there is still a gap on the aggregated average.