Refactor tasks code as decorated functions using swh-scheduler 0.0.39
As well as their tests, using celery's pytest fixture and swh-scheduler (0.0.39) fixtures
Concerns:
- swh-archiver swh/devel/swh-archiver!13 (closed)
- swh-deposit swh/devel/swh-deposit!367 (closed)
- swh-indexer swh/devel/swh-indexer!438 (closed)
- swh-lister swh/devel/swh-lister!53 (closed)
- swh-loader-debian swh/devel/swh-loader-debian!13 (closed)
- swh-loader-dir swh/devel/swh-loader-dir!11 (closed)
- swh-loader-git swh/devel/swh-loader-git!128 (closed)
- swh-loader-mercurial swh/devel/swh-loader-mercurial!111 (closed)
- swh-loader-pypi swh/devel/swh-loader-pypi!29 (closed)
- swh-loader-svn swh/devel/swh-loader-svn!192 (closed)
- swh-loader-tar swh/devel/swh-loader-tar!11 (closed)
- swh-vault swh/devel/swh-vault!168 (closed)
Migrated from T1480 (view on Phabricator)