Generated provider schema cannot be instantiated with --with-schema #505

Describe the overall issue and situation

Running the provider plugin generator with --with-schema creates a schema class that remains abstract. The generated class implements supports_strict_mode, while BaseSchema requires the abstract requires_raw_output property.

The generator reports that schema support was added, but calling from_examples raises a TypeError when it tries to instantiate the class.

Steps to reproduce the issue

1. Generate a provider plugin:

   python scripts/create_provider_plugin.py MyProvider --with-schema --no-install

2. Import MyProviderSchema from the generated package.

3. Call MyProviderSchema.from_examples([]).

The call fails with:

TypeError: Can't instantiate abstract class MyProviderSchema without an implementation for abstract method 'requires_raw_output'

Expected behavior

A schema generated by the advertised --with-schema workflow should implement the current BaseSchema contract and be instantiable through from_examples.

Environment

Reproduced on current main at b5fe0ba with Python 3.12.