Implement retry mechanism when the checkout fails

[diegorusso]

We had a few occasions where the checkout action failed with no apparent reason:

• https://github.com/python/cpython/actions/runs/12934438169/job/36075486419?pr=129232
• https://github.com/python/cpython/actions/runs/12918705578/job/36027797316?pr=129203
• https://github.com/python/cpython/actions/runs/12916370948/job/36020416334?pr=129197

When raising a support ticket a tip has been generated.

I couldn't see any retry in the checkout action documentation. In fact, it is not implemented at all:

https://github.com/diegorusso/cpython/actions/runs/12948283932/job/36116629838#step:4:157

Can you actually implement a retry in the checkout action?