Missing `__init__.py` for mellea/stdlib

[psschwei]

When trying to run the tests, got the following error.

$ CICD=1 pytest
=========================================================================== test session starts ===========================================================================
platform linux -- Python 3.12.8, pytest-9.0.0, pluggy-1.6.0
rootdir: /home/paulschw/generative-computing/mellea
configfile: pyproject.toml
plugins: asyncio-1.3.0, anyio-4.11.0, nbmake-1.5.5, Faker-37.12.0
asyncio: mode=Mode.AUTO, debug=False, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function
collected 338 items / 1 error / 1 skipped

================================================================================= ERRORS ==================================================================================
______________________________________________________ ERROR collecting mellea/stdlib/components/test_based_eval.py _______________________________________________________
ImportError while importing test module '/home/paulschw/generative-computing/mellea/mellea/stdlib/components/test_based_eval.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
../../.local/share/uv/python/cpython-3.12.8-linux-x86_64-gnu/lib/python3.12/importlib/__init__.py:90: in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
mellea/stdlib/components/__init__.py:4: in <module>
    from ...core import (
E   ImportError: attempted relative import beyond top-level package
============================================================================ Skipped Examples =============================================================================
Examples with the following names were skipped because they cannot be easily run in the pytest framework; please run them manually:
__init__.py
pii_serve.py
simple_rag_with_filter.py
mcp_example.py
101_example.py
client.py
========================================================================= short test summary info =========================================================================
ERROR mellea/stdlib/components/test_based_eval.py
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
====================================================================== 1 skipped, 1 error in 23.38s =======================================================================

Re-adding the mellea/stdlib/__init__.py file seemed to fix it.