When phpunit.xml has <coverage> and <source> sections, PHPUnit
auto-initializes its code coverage driver which takes over
xdebug's coverage APIs. TIA's recorder then gets empty data
from xdebug_get_code_coverage(), resulting in zero recorded
edges and no graph being saved.
Inject --no-coverage into the arguments when TIA enters its
own recording mode (not piggybacking on an explicit coverage
report). This tells PHPUnit to ignore XML-configured coverage
reports, leaving xdebug free for TIA's per-test recording.
Having <coverage> and <source> in phpunit.xml is standard for
any project that generates coverage reports. Without this fix,
users must manually pass --no-coverage alongside --tia, which
is an unnecessary footgun.