pypi.loader: Fix PyPILoader._last_snapshot implementation
While reading the PyPI loader implementation for getting inspiration for the npm one, I stumbled across that piece of code that feels wrong to me.
Prior to that fix, last snapshot of a PyPI project was returned only if it contains more than 1000 branches/releases, which is pretty rare.
Based on my understanding, this means that each time a PyPI project is visited again, already ingested releases are processed again but this should not happen.
Migrated from D710 (view on Phabricator)