issue: #42165
Implement dynamic task execution capacity calculation based on QueryNode
CPU core count instead of static configuration for better resource
utilization.
Changes include:
- Add CpuCoreNum() method and WithCpuCoreNum() option to NodeInfo
- Implement GetTaskExecutionCap() for dynamic capacity calculation
- Add QueryNodeTaskParallelismFactor parameter for tuning
- Update proto definition to include cpu_core_num field
- Add unit tests for new functionality
This allows QueryCoord to automatically adjust task parallelism based on
actual hardware resources.
Signed-off-by: Wei Liu <wei.liu@zilliz.com>