tweak setup.py to fall back to importing setup from setuptools if distutils is not available
#4688
| Job | Run time |
|---|---|
| 23s | |
| 23s | |
| 32s | |
| 19s | |
| 13s | |
| 55s | |
| 29s | |
| 48s | |
| 4m 2s |