Python: Allow for structured outputs with Ollama (#12533)

### Motivation and Context

Ollama's execution settings currently only allow for `json` literal. We
also want to support structured outputs for models that support it.

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### Description

- Closes #12355
- Supersedes #12386

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### Contribution Checklist

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- [X] The code builds clean without any errors or warnings
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Author: moonbox3

python/semantic_kernel/connectors/ai/ollama/ollama_prompt_execution_settings.py

@@ -10,7 +10,7 @@
 class OllamaPromptExecutionSettings(PromptExecutionSettings):
     """Settings for Ollama prompt execution."""
 
-    format: Literal["json"] | None = None
+    format: Literal["json"] | dict[str, Any] | None = None
     options: dict[str, Any] | None = None