Import some package bumps from aports

py3-cairosvg: bump pkgrel

sr.ht/py3-cairosvg: re-introduce flake8/isort plugins

sr.ht/py3-cairosvg: drop isort/flake8 plugins

sr.ht/py3-cairosvg: upgrade to 2.4.2

py3-cairosvg: import from testing, update