Weird issue with redis object cache, transients, css parsed cache and output

### Bug Description

Sometimes the AMP pages are displayed without any CSS but restarting or flushing the object cache solves the issue. I suspect that the aproach wich caches the parsed CSS is not working well with redis object cache.

### Expected Behaviour

Expected behaviour is that the pages are being displayed with the CSS styles without issues.

### Screenshots

_No response_

### PHP Version

8.3

### Plugin Version

Latest one

### AMP plugin template mode

Transitional

### WordPress Version

Latest one

### Site Health

_No response_

### Gutenberg Version

_No response_

### OS(s) Affected

_No response_

### Browser(s) Affected

All

### Device(s) Affected

All

### Acceptance Criteria

_No response_

### Implementation Brief

_No response_

### QA Testing Instructions

Try to test it with a wordpress redis object cache plugin installed

### Demo

_No response_

### Changelog Entry

_No response_

Start by reproducing the missing-CSS behavior with a WordPress Redis object cache plugin installed, using the parsed CSS and transient caching paths as the focus. Confirm the behavior is understood and that AMP pages consistently render their CSS without requiring an object-cache restart or flush.

Written by the indexing model from the issue text.