Clobber cached checkouts on gclient sync failures.

This is affecting mac try builders where there is a very high
probability tasks can get cancelled in the middle of a sync leaving a
bad cache that will fail all the following tasks.

Change-Id: I2753d6b94afb0918702fd3c6d89402c6caf50d3a
Bug: https://github.com/flutter/flutter/issues/58516
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/3280
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
Reviewed-by: Tong Wu <wutong@google.com>
2 files changed
tree: dcb2c1731cb476ae8f29b32298932edb774f7206
  1. infra/
  2. recipe_modules/
  3. recipes/
  4. .gitignore
  5. .style.yapf
  6. recipes.py