Bind groups getting created while zooming / panning out

[0531769](https://github.com/GraphiteEditor/Graphite/commit/0531769c4181397aa0ad36bae25163cb878f42b3) (2026-02-22): Cache Vello render output as stitchable textures ([#3722](https://github.com/GraphiteEditor/Graphite/pull/3722))

Introduced in this commit , when you try to zoom in / out an image there are additional bind groups created which should not be the case . You can use this extension to checkout the bind groups getting created for firefox

https://addons.mozilla.org/en-US/firefox/addon/webgpu-inspector/

or for chrome

https://chromewebstore.google.com/detail/webgpu-inspector/holcbbnljhkpkjkhgkagjkhhpeochfal

首先比较引入将缓存的 Vello 渲染输出作为 stitchable textures 的 commit 0531769，并使用 WebGPU Inspector 扩展重现缩放或平移操作。跟踪该交互过程中创建的 bind groups，并确认缩放或平移不再创建报告中显示的额外组。

由索引模型根据 Issue 内容生成。