Photon: Images larger than 6000px set to full-width+full size appear blurry with Photon enabled

### Quick summary

A very large image is added 6000px width+


It's then added as an image block to a page.

The block is then set to full width and the image becomes blurred and loses all it's cripness

### Steps to reproduce

A very large image is added 6000px width+


It's then added as an image block to a page.

The block is then set to full width and the image becomes blurred and loses all it's cripness

### What you expected to happen

The image to remain sharp

### What actually happened

It's blurred

### Context

* Tried to compress the image and reupload it at 2000 width. It still blurred.
* Theme: Shoreditch.
* Tried on a test site with Shoreditch and it does the same.
* Changed theme to a blockbase one. Also blurred
* Tried turning off jetpack image settings. No change
* 4935720-zd

### Simple, Atomic or both?

Atomic

### Theme-specific issue?

_No response_

### Browser, operating system and other notes

_No response_

### Reproducibility

Consistent

### Severity

Some (< 50%)

### Available workarounds?

No but the platform is still usable

### Workaround details

_No response_

The issue names no file, test, or entry point. First reproduce the problem with a 6000px-plus image in a WordPress image block using Photon and full-width/full-size settings, then trace the generated image and rendering path; done means the image remains sharp without breaking the documented reproduction case.

Written by the indexing model from the issue text.