[Core] Fix community pipeline initialization compatibility with primitive types

[ProgramerSalar]

What does this PR do?

This PR fixes Issue #6969.

When the image_encoder argument was added to the base pipeline, it shifted the order of positional arguments. This caused legacy community pipelines (like Bingsu/regional-prompter) that instantiate via super().__init__(...) with an ordered list to accidentally pass primitive types (like booleans) into the image_encoder slot. This resulted in an AttributeError: 'bool' object has no attribute '__module__' when the library attempted to register the module.

This PR adds a defensive type check isinstance(module, (bool, int, float, str)) inside _fetch_class_library_tuple to safely return None, None, allowing these legacy community pipelines to load seamlessly without crashing.

Fixes #6969

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline?
• Did you read our philosophy doc (important for complex PRs)?
• Was this discussed/approved via a GitHub issue or the forum? Please add a link to it if that's the case.
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

Core library:

• Pipelines and pipeline callbacks: @yiyixuxu and @asomoza
• General functionalities: @sayakpaul