- Update composer.json for Typo3 v12
- Add missing dependency for `typo3/cms-scheduler`
- Add version restriction for phpunit v9 (phpunit v10 has breaking changes)
- Upgrade dependency `typo3/testing-framework` to v7, which is compatible with Typo3 v11 and v12
- Fix basic problems with extension configuration (see Typo3 Feature #96733)
- Replace `TYPO3_MODE` references (see Typo3 Deprecation #92947)
- Remove phpstan ignore rule `TYPO3_MODE not found`, which is not required any more
- Fix flash message rendering (see Typo3 Depcrecation #97787)
- Fix `SolrSearch` implementation by extending from `Query` class (see Typo3 Breaking #96044)
- Avoid initialization via constructor in `AbstractController` (required to access $request when migrating to v13, see Typo3 Deprecation #99615)
- Fix NewTenantController by using dependency injection (see Typo3 Manual)
- Return ResponseInterfaces in controller actions (see Typo3 Deprecation #92784)
- Change `forward` calls to `redirect` in controller classes (see Typo3 Deprecation #92815)
- Remove reference to old `ObjectManager` (see Typo3 Deprecation #94619)
- Determine login status via Context class instead of `$GLOBALS["TSFE"]` (see Typo3 Manual)
- Update GitHub CI tests to Typo3 v11 (with PHP 7.4) and v12 (with PHP 8.1)
- Remove columns `cruser_id`, `t3ver_oid`, `t3ver_wsid`, `t3ver_state`, `t3ver_stage` from test fixtures, which are not available in Typo3 v12 any more (see Typo3 Breaking #98024)
- Fix OAI-PMH template in case of request without verb or other parameters
- Fix various undefined array key issues that are raised when using PHP 8+

… 32 characters since Typo3 v10.4.

See [ext_tables.sql](https://github.com/TYPO3/typo3/blob/808ef61a53bc1e7ef65b715c13727b0f2d086c24/typo3/sysext/frontend/ext_tables.sql#L29) for Typo3 frontend module.

 Typo3 v12 changes `addQueryString` parameter, see Typo3 Feature #98488.