fix(spaces): add missing custom nodes for GGUF / preprocessors / math / mxToolkit

Workflow class_types audit revealed four custom-node packs we hadn't
cloned on Spaces:
- city96/ComfyUI-GGUF → UnetLoaderGGUF (caused current KeyError)
- Fannovel16/comfyui_controlnet_aux → Canny/DW/DepthAnythingV2 preprocessors
- evanspearman/ComfyMath → CM_FloatToInt, CM_IntToFloat
- Smirnov75/ComfyUI-mxToolkit → mxSlider

ComfyUI's caching layer walks every node in the graph during prompt
validation, so even nodes that wouldn't execute on a given preset
(GGUF in T2V, etc.) need to be registered or the KeyError fires
before any sampler runs.

app.py

@@ -38,6 +38,10 @@ CUSTOM_NODES_PINNED: list[tuple[str, str]] = [
     ("https://github.com/rgthree/rgthree-comfy.git", "683836c46e898668936c433502504cc0627482c5"),
     ("https://github.com/Kosinkadink/ComfyUI-VideoHelperSuite.git", "2984ec4c4b93292421888f38db74a5e8802a8ff8"),
     ("https://github.com/pythongosssss/ComfyUI-Custom-Scripts.git", "609f3afaa74b2f88ef9ce8d939626065e3247469"),
+    ("https://github.com/city96/ComfyUI-GGUF.git", "6ea2651e7df66d7585f6ffee804b20e92fb38b8a"),
+    ("https://github.com/Fannovel16/comfyui_controlnet_aux.git", "e8b689a513c3e6b63edc44066560ca5919c0576e"),
+    ("https://github.com/evanspearman/ComfyMath.git", "c01177221c31b8e5fbc062778fc8254aeb541638"),
+    ("https://github.com/Smirnov75/ComfyUI-mxToolkit.git", "7f7a0e584f12078a1c589645d866ae96bad0cc35"),
 ]