.Net: Add support for 'minimal' reasoning effort for {Azure}+OpenAI Connectors #27275

Job	Run time
paths-filter	8s
Python Pre-Merge Integration Tests - AI Services (incl samples using those)	0s
Python Integration Tests - Scheduled run	0s
python-integration-tests-check	7s
Python Pre-Merge Integration Tests - Ollama	0s
Python Pre-Merge Integration Tests - Agents	0s
Python Pre-Merge Integration Tests - Memory (incl samples using those)	0s
Python Pre-Merge Integration Tests - Multi-Modality	0s
	15s

Provide feedback