pypi/loader: Filter out sdist archives not of interest

Some PyPI origins declare sdist archives that cannot be extracted
by swh.core.tarball.uncompress and their content do not match
standard sdist layout.

This is notably the case for sdist files whose extensions are
.deb, .egg, .rpm or .whl.

As those artifacts are not of interest to archive and generate
errors while loading PyPI origins, filter them out from the
sdist files to process.

Related to T3575