Bloom gets stretched when the destination rendertarget isn't a multiple of 16

**Describe the bug**
The bloom buffer gets stretched when the view resolution isn't a multiple of 16

**To Reproduce**
Steps to reproduce the behavior:
1. launch gltf-viewer, enable flare to make it more apparent, then slowly resize the width of the window. every 16 pixels, the bloom will snap into place and be stretched in the intermediate resolutions.

**Expected behavior**
Bloom should scale appropriately with the view resolution

**Screenshots**
Here's a video:

https://github.com/user-attachments/assets/4257831c-31cf-4076-ad4a-e0fcbaaf3ad7

**Logs**
none

**Desktop (please complete the following information):**
- OS: [e.g. iOS]
- GPU: NVIDIA RTX 3060TI
- Backend: OpenGL

**Additional context**