CI: ignore the "flaky" and "timing-dependent" test results

CI: ignore the "flaky" and "timing-dependent" test results

CI builds will now run these tests, but will ignore the results if they
fail. The relevant tests are ones that are sensitive to timing or
have edge conditions that make them more likely to fail on CI servers,
which are often heavily overloaded and slow.

This change only adds two additional tests to be ignored, since the
others already had the flaky keyword.

Closes #11865