Make transcriber_whispy node stateless by removing internal buffer management

[GaijinKa]

Problem

The transcriber_whispy node currently manages buffers internally, which makes it stateful. This approach is not scalable and goes against the principle of keeping nodes stateless and composable.

Proposed Solution

We need a generic mechanism to handle data batching without requiring nodes to maintain internal state. This could potentially be implemented through:

• the next_batch() method

Requirements

• Nodes should be completely stateless
• To handle properly the last messages in the incoming buffer should be a generic, reusable mechanism

Additional context

Nodes should be stateless to achieve:

• Easier testing
• Better composability
• Simplified node implementation
• More predictable behavior
• Easier to reason about data flow