Deleted structure block still shows structure if the RenderSection is now empty

Reproduction steps:

• Fly a few dozens of blocks above ground (i.e. to an empty RenderSection).

• Run `/setblock ~ ~ ~ minecraft:structure_block`

• Change the structure block to SAVE mode.

• Set a structure size of 2x2x2

• Confirm and make sure that the bounding box is shown

• Delete the structure block

• Notice that the bounding box is still shown!

Expected behavior:

Once the structure block is deleted, it should not show a bounding box anymore.

Suggested fix:

This issue seems to happen with global block entities only, which don't get updated for empty sections. Adding `RenderSection.this.updateGlobalBlockEntities(Set.of())` in `RebuildTask#doTask` right before `RenderSection.this.setCompiled(SectionRenderDispatcher.CompiledSection.EMPTY)` seems to fix the issue.