Fix preload functions hanging when assets fail without error callback

[Ady0333]

Resolves #8420

Changes:

• Ensured _decrementPreload() is always called in preload error paths, regardless of whether a user-provided error callback exists.
• Applied this fix consistently across all preload utilities so failed assets no longer block sketch execution.

Files updated:

1. src/image/loading_displaying.js
2. Fixed preload counter decrement in:
3. GIF arrayBuffer error handler
4. Non-GIF img.onerror handler
5. fetch().catch() handler
6. src/typography/loading_displaying.js
7. Fixed opentype.load error handler in loadFont
8. src/io/files.js
9. Fixed error handlers for:
10. loadJSON
11. loadStrings
12. loadTable
13. loadXML
14. loadBytes
15. src/webgl/loading.js
16. Fixed unsupported file type error path in loadModel
17. Behavior before:
18. Asset fails + no error callback → preload never completes
19. Sketch stuck indefinitely on “Loading…”
20. setup() / draw() never execute
21. Behavior after:
22. Asset fails → error is logged (or callback called)
23. Preload counter decrements correctly
24. setup() executes, allowing sketches to continue gracefully

PR Checklist

• [✔️] npm run lint passes
• [Inline reference] is included / updated
• [Unit tests] are included / updated

[Ady0333]

Hi @davepagurek, Greetings !!
This PR ensures _decrementPreload() is always called on preload errors, even when no failure callback is provided, preventing sketches from hanging indefinitely on “Loading…”.

Happy make any adjustments if needed.