[cipd] delete bad cache files when failing do deploy them.

cipd/client/cipd/local/fs.go

Index: cipd/client/cipd/local/fs.go
diff --git a/cipd/client/cipd/local/fs.go b/cipd/client/cipd/local/fs.go
index e30595e4ba2c7e512c9a63df63604a3403c84b0c..99784cace9ba0f20bf0500a21eae6a034e8ab3b0 100644
--- a/cipd/client/cipd/local/fs.go
+++ b/cipd/client/cipd/local/fs.go
@@ -256,7 +256,9 @@ func (f *fsImpl) EnsureFileGone(ctx context.Context, path string) error {
 	}
 	if err = os.Remove(path); err != nil && !os.IsNotExist(err) {
 		logging.Warningf(ctx, "fs: failed to remove %s - %s", path, err)
-		return err
+		if f.moveToTrash(ctx, path) == "" {
+			return err
+		}
 	}
 	return nil
 }