[Self-filed] Switch back to rules_python when their issues are fixed

[cpsauer]

We'd switched to rules_python to get a hermetic python interpreter and to be able to make sure that everyone was on the same python version, rather than relying on system python. However, a number of issues caused us to revert for now.

Please see

• target <target @@hedron_compile_commands//:_refresh_all> does not have rules_python PyRuntimeInfo or builtin PyRuntimeInfo #163
• bug: PyRuntimeInfo provided by py_binary doesn't match PyRuntimeInfo symbol from rules_python bazelbuild/rules_python#1732
• ModuleNotFoundError: No module named 'orjson.orjson' #165
• (rules_python issue to come)
• The current user is root, please run as non-root when using the hermetic Python interpreter #166
• non-root requirement seems too much for an ordinary user of rules_python bazelbuild/rules_python#1169

[cpsauer]

[Intentional blank comment, added to make it clear from the table view that this isn't a user issue lacking a response.]

[cpsauer]

Blocks #148