`pkgutil.get_data()` get confused by local modules for module installed with `pip install --editable`

Bug report

Bug description:

First execute in bash:

git clone https://github.com/pyx-project/pyx
cd pyx
pip install -e .
cd pyx  # important! Now the directory is inside two layers of /pyx
python

Then execute in Python:

import pkgutil
pkgutil.get_data("pyx", "data/pyxrc")

Return value is None.

Note that the return value would not be None if either -e or the second cd is omitted --- which shows that the data file is correctly available.

CPython versions tested on:

3.11

Operating systems tested on:

No response

Reproduce the bash and Python steps from the report, focusing on the pkgutil.get_data entry point after pip install -e . and the nested cd pyx. Trace why it returns None for data/pyxrc in that context, then verify that the same lookup returns the available data without requiring either workaround.