codecov.yml: suppress coverage errors more
codecov.yml: suppress coverage errors more

Somehow informational:true is not enough to not produce errors.
We are constantly getting nacks on PRs like:
  x codecov/patch — 59.2% of diff hit (target 65.3%)
Add back and relax target and treshold.

google/syzkaller,xairy/syzkaller,google/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller,google/syzkaller,google/syzkaller,xairy/syzkaller