Add allowlist_externals=make to fix tox 4

[hugovk]

Calling make (without allowlist_externals = make in tox.ini) gives a deprecation warning in tox 3 and an error in tox 4.

Add allowlist_externals = make to remove the warning and error.

Also format tox.ini with https://github.com/tox-dev/tox-ini-fmt

Before

tox 3.27.1

Warns about using make without allowlist_externals

$ tox -e py311
GLOB sdist-make: /Users/hugo/github/Pillow/setup.py
py311 create: /Users/hugo/github/Pillow/.tox/py311
py311 installdeps: cffi, numpy
py311 inst: /Users/hugo/github/Pillow/.tox/.tmp/package/5/Pillow-9.4.0.dev0.zip
py311 installed: attrs==22.1.0,build==0.9.0,certifi==2022.12.7,cffi==1.15.1,charset-normalizer==2.1.1,check-manifest==0.49,coverage==6.5.0,defusedxml==0.7.1,docutils==0.19,idna==3.4,iniconfig==1.1.1,markdown2==2.4.6,numpy==1.23.5,olefile==0.46,packaging==22.0,pep517==0.13.0,Pillow @ file:///Users/hugo/github/Pillow/.tox/.tmp/package/5/Pillow-9.4.0.dev0.zip,pluggy==1.0.0,pycparser==2.21,Pygments==2.13.0,pyroma==4.1,pytest==7.2.0,pytest-cov==4.0.0,pytest-timeout==2.1.0,requests==2.28.1,trove-classifiers==2022.12.1,urllib3==1.26.13
py311 run-test-pre: PYTHONHASHSEED='3385010674'
py311 run-test: commands[0] | make clean
WARNING: test command found but not installed in testenv
  cmd: /usr/bin/make
  env: /Users/hugo/github/Pillow/.tox/py311
Maybe you forgot to specify a dependency? See also the allowlist_externals envconfig setting.

DEPRECATION WARNING: this will be an error in tox 4 and above!
python3 setup.py clean
...

tox 4.0.8

As promised, fails when using make without allowlist_externals

$ tox -e py311
.pkg: _optional_hooks> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: get_requires_for_build_sdist> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: prepare_metadata_for_build_wheel> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: build_sdist> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
py311: install_package> python -I -m pip install --force-reinstall --no-deps /Users/hugo/github/Pillow/.tox/.tmp/package/4/Pillow-9.4.0.dev0.tar.gz
py311: commands[0]> make clean
py311: failed with make is not allowed, use allowlist_externals to allow it
.pkg: _exit> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
  py311: FAIL code 1 (24.65 seconds)
  evaluation failed :( (24.68 seconds)

After

tox 3.27.1

No warning

$ ⌂10.76 [hugo:~/github/Pillow] fix-tox-4+* ± tox -e py311
GLOB sdist-make: /Users/hugo/github/Pillow/setup.py
py311 inst-nodeps: /Users/hugo/github/Pillow/.tox/.tmp/package/5/Pillow-9.4.0.dev0.zip
py311 installed: attrs==22.1.0,build==0.9.0,certifi==2022.12.7,cffi==1.15.1,charset-normalizer==2.1.1,check-manifest==0.49,coverage==6.5.0,defusedxml==0.7.1,docutils==0.19,idna==3.4,iniconfig==1.1.1,markdown2==2.4.6,numpy==1.23.5,olefile==0.46,packaging==22.0,pep517==0.13.0,Pillow @ file:///Users/hugo/github/Pillow/.tox/.tmp/package/5/Pillow-9.4.0.dev0.zip,pluggy==1.0.0,pycparser==2.21,Pygments==2.13.0,pyroma==4.1,pytest==7.2.0,pytest-cov==4.0.0,pytest-timeout==2.1.0,requests==2.28.1,trove-classifiers==2022.12.1,urllib3==1.26.13
py311 run-test-pre: PYTHONHASHSEED='1473613542'
py311 run-test: commands[0] | make clean
python3 setup.py clean
...

tox 4.0.8

No error

$ tox -e py311
py311: install_deps> python -I -m pip install cffi numpy
.pkg: _optional_hooks> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: get_requires_for_build_sdist> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: prepare_metadata_for_build_wheel> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
.pkg: build_sdist> python /Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/site-packages/pyproject_api/_backend.py True setuptools.build_meta __legacy__
py311: install_package_deps> python -I -m pip install check-manifest coverage defusedxml markdown2 olefile packaging pyroma pytest pytest-cov pytest-timeout
py311: install_package> python -I -m pip install --force-reinstall --no-deps /Users/hugo/github/Pillow/.tox/.tmp/package/5/Pillow-9.4.0.dev0.tar.gz
py311: commands[0]> make clean
python3 setup.py clean
...