Revert MC-101556

Reverts the "fix" for MC-101556 (only affects ``1.21.5``).

Makes nether portals/chunk loaders work properly again.

Please note that the "fix" for MC-101556 was reverted by Mojang in ``25w16a`` (``1.21.6``) and the mod is no longer required in these versions.

The mod itself is extremely minimalistic and only a single line of code was patched.