Python 3.8 support

[Paolo]

Describe the bug

Depot tools now requires python 3.8

To Reproduce
Steps to reproduce the behavior:

1. Run pipeline
2. Error will happen within the build step (see image)

Expected behavior

Building with the new version of depot tools should be working

[Paulo Coutinho]

Hi,

I have updated everything.

You can now use the latest version.

Thanks.