Filter out sdist archives that are not of interest

Some PyPI origins declare sdist archives in formats that are not supported by swh.core.tarball.uncompress, for instance .deb, .egg, .rpm or .whl. This leads to errors when trying to load such origins and generates a lot of noise in sentry reports.

As the content of those archives does not match standard sdist format (there is no PKG-INFO file for instance), we should filter them out from the artifacts to process for a PyPI origin.