refactor: update stats/base/dmeanvar native addon from C++ to C
          
            #11097
        
      | Job | Run time | 
|---|---|
| 2s | |
| 2s | 
stats/base/dmeanvar native addon from C++ to C
          
            #11097
        
| Job | Run time | 
|---|---|
| 2s | |
| 2s |