Issue #3424436 by mondrake, longwave: [11.x] Remove deprecated code from the Diff component

core/lib/Drupal/Component/Diff/Diff.php

core/lib/Drupal/Component/Diff/Engine/DiffEngine.php

core/lib/Drupal/Component/Diff/Engine/DiffOp.php

core/lib/Drupal/Component/Diff/Engine/DiffOpAdd.php

core/lib/Drupal/Component/Diff/Engine/DiffOpChange.php

core/lib/Drupal/Component/Diff/Engine/DiffOpCopy.php

core/lib/Drupal/Component/Diff/Engine/DiffOpDelete.php

core/lib/Drupal/Component/Diff/composer.json

core/phpstan-baseline.neon

...sts/Drupal/Tests/Component/Diff/Engine/DiffEngineTest.php

core/tests/Drupal/Tests/Component/Diff/Engine/DiffOpTest.php