The @dataProvider annotation should be a static function, check and make data provider in the extension, at least:
- ContemporaryCheckerTest with provideStandardStatements
- HtmlTableBuilderTest with toHtmlDataProvider
- WikibaseQualityConstraintsHooksTest with provideChanges
static and adjust the usages (More infos at T332865).
Initial work was done in 0d89717c1f999529bdcc5f5cf313f7b1fbdb7284