Truncate cascade on non-mysql database platforms for Testbase

[lleicher-sg]

When using typo3/testing-framework with Postgres, you get the following error for tables with foreign keys:

PDOException: SQLSTATE[0A000]: Feature not supported: 7 ERROR:  cannot truncate a table referenced in a foreign key constraint
DETAIL:  Table "tx_groups_members_mm" references "fe_users".
HINT:  Truncate table "tx_groups_members_mm" at the same time, or use TRUNCATE ... CASCADE.

(I am using Postgres 15)

This is caused by \TYPO3\TestingFramework\Core\Testbase::truncateAllTablesForOtherDatabases, because the cascade argument is false by default.

This PR simply sets cascade to true.
Given that only the PostgreSQLPlatform uses the parameter atm, I don't think there will be any side effects.

[sbuerk]

Note

TYPO3 does not support/guarentee foreign key support, neither
in the database analyzer stack nor in any API like datahandler,
extbase and so forth. Something not easily doable anyway.

Looking into the pr later, I guess we may take it.