Python: Fix "implicit namespace packages" migration

[amotl]

About

... by omitting __init__.py from crate namespace package altogether, see "PEP 420" [1] and "Package Discovery and Namespace Package » Finding namespace packages" [2].

[1] https://peps.python.org/pep-0420/
[2] https://setuptools.pypa.io/en/latest/userguide/package_discovery.html#namespace-packages

References

• Python: Migrate to use "implicit namespace packages" (PEP 420). Dependencies: Use crate>=1.0.0.dev2 for validation purposes. CI: Use Python 3.11, up from 3.8. #326
• Python: Fix "implicit namespace packages" migration crate-python#675
• Python: Fix "implicit namespace packages" migration crash#453

[amotl]

ok to test

[seut]

We probably can/should remove any __init__.py file, e.g. https://github.com/crate/crate-qa/blob/master/tests/bwc/__init__.py?

[amotl]

We probably can/should remove any init.py file?

I am not sure: The test directory is no package directory at all, at one hand. On the other, it is treated as such more often than not, in development. In this case, it is still not a namespace package.