Unable to parse Build/WebGL.framework.js.gz! This can happen if build compression was enabled but web server hosting the content was misconfigured to not serve the file with HTTP Response Header "Content-Encoding: gzip" present. Check browser Console and Devtools Network tab to debug.

Console shows this:

WEBGL_debug_renderer_info is deprecated in Firefox and will be removed. Please use RENDERER. WebGL.loader.js:1:9894
The script from “https://gableroux.github.io/unity-rotation-playground/WebGL/Build/WebGL.framework.js.gz” was loaded even though its MIME type (“application/gzip”) is not a valid JavaScript MIME type.
WebGL
Uncaught SyntaxError: illegal character U+001F
WebGL.framework.js.gz:1
[UnityCache] 'https://gableroux.github.io/unity-rotation-playground/WebGL/Build/WebGL.data.gz' successfully revalidated and served from the indexedDB cache WebGL.loader.js:1:14524

Right now, webgl build gets published to
https://gableroux.github.io/unity-rotation-playground/WebGL
instead of
https://gableroux.github.io/unity-rotation-playground/

We can see the folder in here:
https://github.com/GabLeRoux/unity-rotation-playground/tree/gh-pages

As seen in https://github.com/GabLeRoux/unity-rotation-playground/actions/runs/3440771126/jobs/5739611632

Related thread:
https://forum.unity.com/threads/how-to-resolve-incompatibility-between-color-space-and-current-settings.460677/

When using the WebGL module in the editor, we can see a related warning:

In order to build a player, go to 'Player Settings...' to resolve the incompatibility between the Color Space and the current settings.