setup: prepare for pypi upload
related to swh-environment#1242 (closed)
add build/ and dist/ to gitignore
Test Plan
https://test.pypi.org/project/swh-mirror-forge/
Migrated from D501 (view on Phabricator)
related to swh-environment#1242 (closed)
add build/ and dist/ to gitignore
https://test.pypi.org/project/swh-mirror-forge/
Migrated from D501 (view on Phabricator)