[BUGFIX] Cast return value of method formMaxWidth to int

AbstractFormElement->formMaxWidth declares its
return type as of type int. But the ceil function
returns float. The return value is now cast to int
to prevent unexpected values.

Resolves: #97108
Releases: main, 11.5
Change-Id: I2426a0a1f2bf78ef89ad0eec89158498136b0885
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73830


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