What is the bug or the crash?

Stumbled on a serious issue with QGIS' tasks framework when testing out a symbology for QGIS' constributors map.

When rendering a vector layer styled with a raster marker symbol that fetches remote images, the generated network fetching tasks are never completed. They then linger in the task manager, and prevents the user from being able to exit QGIS.

In action:

Steps to reproduce the issue

1. Open the following project in QGIS:

contributors.zip

(You might need to wait for all the visible avatar images to be downloaded and cached, and then re-open the project)

2. Notice the tasks manager progress bar within the status bar spins forever
3. Try to exit QGIS, good luck :)

Versions

QGIS 3.44 and QGIS 3.99

Supported QGIS version

• I'm running a supported QGIS version according to the roadmap.

New profile

• I tried with a new QGIS profile

Additional context

No response