Clobber checkout directory by default.

This is to prevent issues with git tags not being cleaned.

Change-Id: I144e781dd5bec2a215b9717b7ca648640411fd95
Bug: https://github.com/flutter/flutter/issues/62146
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/4721
Reviewed-by: Nurhan Turgut <nurhan@google.com>
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
78 files changed
tree: 74e3dd0b40e2512515ea9ad122c2ae465d32dcf6
  1. infra/
  2. recipe_modules/
  3. recipes/
  4. .gitignore
  5. .style.yapf
  6. OWNERS
  7. recipes.py