bisect-kit: Handle the case where DEPS are removed accidentally.

DEPS file can reference to child DEPS files (recursedeps). Normally the
child DEPS file should exist. However in some cases the child DEPS are
removed accidentally while the parent still reference to it. When
building chrome revlist, trying to read an absent DEPS file result in a
fatal error.

This revision tries to ignore such errors.

BUG=b:327248973
TEST="bisect_cr_localbuild_internal.py init && run_formatter.sh &&
run_test.sh

Change-Id: I0c8effefcf76068d456440288d65e957549539de
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/bisect-kit/+/5367781
Reviewed-by: MD Nayeem Jahan Rafi <njrafi@chromium.org>
Tested-by: Cheng-Yu Lee <cylee@google.com>
Commit-Queue: Cheng-Yu Lee <cylee@google.com>
1 file changed