StencilEffect doesn't work on 1.18

[caoimhebyrne]

Describe the bug Elementa's StencilEffect doesn't work in 1.18 as the enableStencil function doesn't have any implementation for versions less than 1.15.

To Reproduce Steps to reproduce the behavior:

1. Call StencilEffect.enableStencil() in your mod's initializer
2. Add the StencilEffect to your component

Expected behavior The component should be scissored around the parent component

Additional context To enable stencils in 1.18, I found this gist, but I wasn't able to get it working properly.

[mew]

hi connor