revert changes in _is_package_available

[MekkCyber]

What does this PR do?

Reverts #41411, because for some packages like optimum we don't have loaders as expected from most packages.

[vasqu]

I think the same applies to FA3 for example 😢

[MekkCyber]

I think in FA3 we do have loaders

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[vasqu]

Nope, just checked. Spec is there, loader is None

Have it locally installed

[MekkCyber]

they don't have an __init__.py file ?

[BenjaminBossan]

This fixes the original issue, thanks for the quick action.

[vasqu]

They do, but they don't make it as an importable function as per the pkg name --> "flash_attn_3" is not importable and the loader check fails here.

[MekkCyber]

I'm not sure what you mean @vasqu, for example here, just creating the __init__.py file makes the folder loadable :

/scripts_training$ python
Python 3.12.11 (main, Sep 18 2025, 19:47:19) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib.util
>>> importlib.util.find_spec("test")
>>> ^D
(dev) /scripts_training$ mkdir test
(dev) /scripts_training$ python
Python 3.12.11 (main, Sep 18 2025, 19:47:19) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib.util
>>> importlib.util.find_spec("test")
ModuleSpec(name='test', loader=None, submodule_search_locations=_NamespacePath(['/scripts_training/test', '/scripts_training/test']))
>>> ^D
(dev) /scripts_training$ touch test/__init__.py
(dev) /scripts_training$ python
Python 3.12.11 (main, Sep 18 2025, 19:47:19) [Clang 20.1.4 ] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import importlib.util
>>> importlib.util.find_spec("test")
ModuleSpec(name='test', loader=<_frozen_importlib_external.SourceFileLoader object at 0x7f768f8f0110>, origin='/scripts_training/test/__init__.py', submodule_search_locations=['/scripts_training/test'])
>>>