Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
Unvendor distutils. Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
package:
  name: mne
  version: 0.18.2

source:
  sha256: aa2e72ad3225efdad39b05e67cd5c88dbd5c3fabf5e1705e459347131f114bc6
  url: https://files.pythonhosted.org/packages/42/ec/08afc26ea6204473031f786d0f3034119a5a138d40062b37fbf578c81c01/mne-0.18.2.tar.gz

requirements:
  run:
    - numpy
    - scipy

test:
  imports:
    - mne

package:
  name: mne
  version: 0.18.2

source:
  sha256: aa2e72ad3225efdad39b05e67cd5c88dbd5c3fabf5e1705e459347131f114bc6
  url: https://files.pythonhosted.org/packages/42/ec/08afc26ea6204473031f786d0f3034119a5a138d40062b37fbf578c81c01/mne-0.18.2.tar.gz

requirements:
  run:
    - distutils
    - numpy
    - scipy

test:
  imports:
    - mne
