PHPUnit 10 marks empty data provider as invalid with the text "Empty data set provided by data provider" and count this as errors.
Some of the provider of the abstract `AbstractSchemaTestBase` are designed to return empty array in case there is no abstract schema change folder.
Throwing an exception (like markSkipTest) does not work under PHPUnit 10.
Example from FlaggedRevs:
```
1) MediaWiki\Extension\FlaggedRevs\Tests\Structure\FlaggedRevsSchemaTest::testSchemaChangesAreValid
The data provider specified for MediaWiki\Extension\FlaggedRevs\Tests\Structure\FlaggedRevsSchemaTest::testSchemaChangesAreValid is invalid
Empty data set provided by data provider
FlaggedRevs\tests\phpunit\structure\FlaggedRevsSchemaTest.php:49
2) MediaWiki\Extension\FlaggedRevs\Tests\Structure\FlaggedRevsSchemaTest::testSchemaChangesHaveAutoGeneratedFiles
The data provider specified for MediaWiki\Extension\FlaggedRevs\Tests\Structure\FlaggedRevsSchemaTest::testSchemaChangesHaveAutoGeneratedFiles is invalid
Empty data set provided by data provider
FlaggedRevs\tests\phpunit\structure\FlaggedRevsSchemaTest.php:89
```