--recursive fail to parse folder with __init__.py at the root when using relative path

[CareF]

Bug description

# folder struct
./__init__.py
./a.py # same goes if a.py is in a subfolder

# __init__.py is empty

# a.py includes anything that may trigger an error report like:

def foo():
    unused = 1

Configuration

No response

Command used

pylint --recursive=y ./

Pylint output

None

Expected behavior

Should be like pylint a.py or pylint --recursive=y $(pwd)

************* Module testpy.a
a.py:1:0: C0114: Missing module docstring (missing-module-docstring)
a.py:1:0: C0116: Missing function or method docstring (missing-function-docstring)
a.py:1:0: C0104: Disallowed name "foo" (disallowed-name)
a.py:2:4: W0612: Unused variable 'unused' (unused-variable)

------------------------------------------------------------------
Your code has been rated at 0.00/10 (previous run: 0.00/10, +0.00)

Pylint version

pylint 3.0.2
astroid 3.0.1
Python 3.11.6 (main, Oct  2 2023, 20:46:17) [Clang 14.0.0 (clang-1400.0.29.202)]

OS / Environment

MacOS

Additional dependencies

No response

[CareF]

I can track it to L146 at lint/expand_modules.py, where

        if has_init or is_namespace or is_directory:
            for subfilepath in modutils.get_module_files(
                os.path.dirname(filepath), ignore_list, list_all=is_namespace
            ):

filepath is __init__.py and os.path.dirname(filepath) is empty str when the bug is triggered, but some valid path when it is normal.