checkout seems to be failing for ubuntu 20 recently:
```
Deleting the contents of '/__w/wezterm/wezterm'
Initializing the repository
/usr/bin/git init /__w/wezterm/wezterm
Initialized empty Git repository in /__w/wezterm/wezterm/.git/
/usr/bin/git remote add origin https://github.com/wez/wezterm
Error: fatal: unsafe repository ('/__w/wezterm/wezterm' is owned by someone else)
To add an exception for this directory, call:
git config --global --add safe.directory /__w/wezterm/wezterm
Error: The process '/usr/bin/git' failed with exit code 128
```
Try reverting this as a workaround.
