mwscript: Containerize MediaWiki script execution
Run all MediaWiki PHP scripts using Docker.
This will allow us to run certain scap commands in environments other
than the deployment host (such as release hosts) without installing a
large number of MediaWiki dependencies.
Provide a new mwscript module and mwscript.Runtime class that
implements mwscript and shell execution using Docker. The latter
replaces some commands that were previously executed using sudo.
Refactor tasks and main modules to use mwscript.Runtime instead of
sudo_check_call.
Bug: T369115