pyright gcg: Cast a bunch of stuff

[tomtseng]

Changes

Fix some pyright errors.

• Imports: Added Callable, Any, cast from typing
• Type fixes: callable → Callable[..., Any] | None, not_allowed_ids: Tensor = False → Tensor | None = None
• embedding_layer: torch.nn.Module → torch.nn.Embedding (via cast)
• Tokenizer calls: Wrapped 10 tokenizer(...)["input_ids"] patterns with cast(Tensor, ...) to handle Encoding stub mismatch
• apply_chat_template: Added assert isinstance(template, str) + narrowed bos_token to str
• init_buffer_ids: Declared init_buffer_ids: Tensor before if/else, changed logger.error to raise RuntimeError in except branch to ensure binding
• spearmanr: Used pyright: ignore for incomplete scipy stubs