These were disabled long ago, but nowadays the intermittent filter can
ignore them when they flake. In addition, running them will allow us to
know if they are still intermittent or not since all intermittent
failures are tracked in GitHub via mentions on issues.
Testing: This is a change to test configuration.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Most tests were only being run for layout-2013, not for layout-2020.
This wasn't great since layout-2020 is now the default.
So this patch unifies the lists of included tests for both layouts.
For layout-2013 this implies adding css/css-content/, css/css-logical/
and css/css-masking/clip/.
For layout-2020 this implies adding several additional css tests, and
also tests like dom/, js/, html/, etc.
