Upgrade restrictedpython to 4.0b4

[fabaff]

Description:

Commit log: https://github.com/zopefoundation/RestrictedPython/commits/master

Example entry for configuration.yaml (if applicable):

python_script:

Test script:

entities = hass.states.entity_ids()

logger.info(entities)

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.