[BUG] AnonymizeIP not anonymizing by octets

[dev-rke]

Describe the bug
AnonymizeIP won't anonymize by octets for IPv4.

To Reproduce
Copy applyIpV4Mask method into an interactive PHP shell and run these commands:

php > echo applyIpV4Mask("192.168.123.5", 2) . PHP_EOL;
192.168.123
php > echo applyIpV4Mask("192.168.123.15", 2) . PHP_EOL;
192.168.123.
php > echo applyIpV4Mask("192.168.123.15", 4) . PHP_EOL;
192.168.12
php > echo applyIpV4Mask("192.168.123.15", 3) . PHP_EOL;
192.168.123
php > echo applyIpV4Mask("192.168.123.153", 3) . PHP_EOL;
192.168.123.
php > echo applyIpV4Mask("192.168.123.153", 1) . PHP_EOL;
192.168.123.15
php > echo applyIpV4Mask("192.168.123.15", 1) . PHP_EOL;
192.168.123.1
php > echo applyIpV4Mask("192.168.123.1", 1) . PHP_EOL;
192.168.123.

Expected behavior
I'd expect the last octet is set to 0.
Example:
User has the ip 192.168.123.234. In the log it should be 192.168.123.0

Used versions (please complete the following information):

• TYPO3 Version: 10 and 11
• EXT:solr Version: tested with 11.0 and 11.5-rc2

Recommendation
I'd recommend to use the IpAnonymizationUtility::anonymizeIp() function of the TYPO3 core to achieve the correct behaviour.
This class is available since TYPO3 v9.2, so it should be available in all current supported TYPO3 versions:
https://github.com/TYPO3/typo3/blob/9.5/typo3/sysext/core/Classes/Utility/IpAnonymizationUtility.php

By the way: thanks for the great extension - i just used 11.5-rc2 with the awesome API in a project.