profiling: improve 3.12 error message for calling lsprof twice
Python 3.12 prevent lsprof to be enabled if it is already enabled. This break
the use of lsprof in `hg serve` as both the initial `serve` command and the
request serving want to profile.
The "stat" profiler (the default) does not have this problem, so we focus on
improving the error message for now.
[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