pip3 should be a symbolic link to pip3.xx

# Feature or enhancement

### Proposal:

This command:
```
python -m ensurepip --upgrade
```
installs 2 identical files: pip3 and pip3.xx

pip3 should be a symlink to pip3.xx, just like python3 is a symlink to python3.xx



### Has this already been discussed elsewhere?

No response given

### Links to previous discussion of this feature:

_No response_