black: move remaining config knobs into toml file

Differential Revision: https://phab.mercurial-scm.org/D7088

black.toml

@@ -1,3 +1,5 b''
 [tool.black]
 line-length = 80
 exclude = 'build/|wheelhouse/|dist/|packages/|\.hg/|\.mypy_cache/|\.venv/|mercurial/thirdparty/|hgext/fsmonitor/pywatchman/|contrib/python-zstandard/'
+skip-string-normalization = true
+quiet = true

contrib/examples/fix.hgrc

@@ -1,15 +1,15 b''
 [fix]
 clang-format:command = clang-format --style file -i
 clang-format:pattern = (**.c or **.cc or **.h) and not "listfile:contrib/clang-format-ignorelist"
 
 rustfmt:command = rustfmt {rootpath}
 rustfmt:pattern = set:**.rs
 
 # We use black, but currently with
 # https://github.com/psf/black/pull/826 applied. For now
 # contrib/grey.py is our fork of black. You need to pip install
 # git+https://github.com/python/black/@d9e71a75ccfefa3d9156a64c03313a0d4ad981e5
 # to have the dependencies for grey.
 #
-# black:command = python3.7 contrib/grey.py --quiet --config=black.toml --skip-string-normalization -
+# black:command = python3.7 contrib/grey.py --config=black.toml -
 # black:pattern = set:**.py - hgext/fsmonitor/pywatchman/** - mercurial/thirdparty/** - "contrib/python-zstandard/**"