[TASK] Avoid failing test value for PHP 8.1.7 strtotime bug

PHP 8.1.7 introduced a bug that it considers the month number 100
to be valid, which breaks one of our tests.

As it is not relevant for the test whether the invalid month is
exactly 100 or 99, we now are using a number that does not trigger
the PHP bug.

https://github.com/php/php-src/issues/8749

Resolves: #97756
Releases: main, 11.5
Change-Id: I2ca2b90a2c1e46f16cfeddda29d80e6a83779b1c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74871


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>