obsstore: break the repo → obstore → repo loop
This should help the garbage collector to do its job. On repository with many
markers, the memory pressure from the obsstore can get quite serious.
[build-system]
requires = ["setuptools", "wheel"]
[tool.black]
line-length = 80
exclude = '''
build/
| wheelhouse/
| dist/
| packages/
| \.hg/
| \.mypy_cache/
| \.venv/
| mercurial/thirdparty/
'''
skip-string-normalization = true
quiet = true