PocketMine-MP allows malicious client data to waste server resources due to lack of limits for explode()

Summary

### Impact Due to lack of limits by default in the [`explode()`](https://www.php.net/manual/en/function.explode.php) function, malicious clients were able to abuse some packets to waste server CPU and memory. This is similar to a previous security issue published in https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-gj94-v4p9-w672, but with a wider impact, including but not limited to: - Sign editing - LoginPacket JWT parsing - Command parsing However, the estimated impact of these issues is low, due to other limits such as the packet decompression limit. ### Patches The issue was fixed in 5.25.2 via d0d84d4c5195fb0a68ea7725424fda63b85cd831. A custom PHPStan rule has also been introduced to the project, which will henceforth require that all calls to `explode()` within the codebase must specify the `limit` parameter. ### Workarounds No simple way to fix this. Given that sign editing is the easiest way this could be exploited, workarounds could include plugins pre-processing `BlockActorDataPacket` to check that the incoming text doesn't have more than 4 parts when split by `\n`.