TilemapChunkMeshCache in TilemapChunk is never used

## Bevy version and features

- main

## What you did

- I was checking the new [TilemapChunk](https://github.com/bevyengine/bevy/blob/main/crates/bevy_sprite_render/src/tilemap_chunk/mod.rs#L48) source code and I noticed that the `TilemapChunkMeshCache` is never used.

https://github.com/bevyengine/bevy/blob/1faaf19c74ea2c030f9e5d9ec82e4ac9cb4ffa3d/crates/bevy_sprite_render/src/tilemap_chunk/mod.rs#L135-L140

## What went wrong

- Either add a new entry to the cache when there is a cache miss or remove the cache at all.

Start by reading crates/bevy_sprite_render/src/tilemap_chunk/mod.rs around lines 135-140 and trace the uses of TilemapChunkMeshCache. The issue is done when the cache is either populated on a cache miss or removed entirely, with the chosen behavior consistent throughout the TilemapChunk implementation.

Written by the indexing model from the issue text.