Run core tests in Safari. Partially addresses https://github.com/pyodide/pyodide/issues/989

It runs, but there are several test failures, I'll open separate issues about those.
package:
  name: lxml
  version: 4.9.0
  top-level:
    - lxml
source:
  sha256: 520461c36727268a989790aef08884347cd41f2d8ae855489ccf40b50321d8d7
  url: https://files.pythonhosted.org/packages/aa/23/bda4e9881090f0f5e33e2efe89aacfa0668eb6e1ab2de28591e2912d78d4/lxml-4.9.0.tar.gz
build:
  cflags: |
    -Wno-implicit-function-declaration
requirements:
  host:
    - libxml
    - libxslt
    - zlib
    - libiconv
  run:
    - beautifulsoup4
    - cssselect
    - html5lib
test:
  imports:
    - lxml
    - lxml.etree
    - lxml.objectify
about:
  home: https://lxml.de/
  PyPI: https://pypi.org/project/lxml
  summary:
    Powerful and Pythonic XML processing library combining libxml2/libxslt
    with the ElementTree API.
  license: BSD

package:
  name: lxml
  version: 4.9.0
  top-level:
    - lxml
source:
  sha256: 520461c36727268a989790aef08884347cd41f2d8ae855489ccf40b50321d8d7
  url: https://files.pythonhosted.org/packages/aa/23/bda4e9881090f0f5e33e2efe89aacfa0668eb6e1ab2de28591e2912d78d4/lxml-4.9.0.tar.gz
build:
  cflags: |
    -Wno-implicit-function-declaration
requirements:
  host:
    - libxml
    - libxslt
    - zlib
    - libiconv
  run:
    - beautifulsoup4
    - cssselect
    - html5lib
test:
  imports:
    - lxml
    - lxml.etree
    - lxml.objectify
about:
  home: https://lxml.de/
  PyPI: https://pypi.org/project/lxml
  summary:
    Powerful and Pythonic XML processing library combining libxml2/libxslt
    with the ElementTree API.
  license: BSD
