Re-enable blur-cube-with-the-effect-renderer validation test

This EffectRenderer fullscreen-pass test rendered all-black on Native because the
native engine did not honor depth-test toggles made through
engine.depthCullingState.depthTest (used by EffectRenderer). Fixed upstream in the
native engine (BabylonJS/Babylon.js#18558); re-enable the test here.

Depends on a babylonjs dependency bump that includes the fix.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bkaradzic

Apps/Playground/Scripts/config.json

@@ -2563,8 +2563,6 @@
             "title": "blur-cube-with-the-effect-renderer",
             "playgroundId": "#4C900K#2",
             "renderCount": 20,
-            "excludeFromAutomaticTesting": true,
-            "reason": "Pixel comparison fails (more than 20% pixels differ)",
             "referenceImage": "blur-cube-with-the-effect-renderer.png"
         },
         {