Pin starlette<0.40 for gradio 4.44.0's old TemplateResponse signature

Starlette 0.40 made `request` the first positional arg of
`TemplateResponse`, but gradio 4.44.0 still calls it with
`(name, context, ...)`. With a newer starlette the context dict
ends up in the `name` slot and Jinja2 raises
`TypeError: unhashable type: 'dict'` on every page load.

Pin starlette<0.40 (and fastapi<0.113 to keep its starlette dep in
range) so the HF Space can actually serve the UI until we upgrade
off gradio 4.44.0.

requirements.txt

@@ -37,4 +37,13 @@ audioop-lts>=0.2.1; python_version >= "3.13"
 # huggingface-hub 0.30. Pin below that until we can upgrade Gradio.
 huggingface-hub>=0.23,<0.30
 
+# Starlette 0.40 made `request` the first positional arg of
+# `TemplateResponse`, but gradio 4.44.0 still calls it as
+# `TemplateResponse(name, context, ...)`. With a newer starlette the
+# context dict lands in the `name` slot and Jinja2 crashes with
+# "unhashable type: 'dict'" the moment the UI is requested. Pin to the
+# pre-break line; fastapi capped to match.
+starlette<0.40
+fastapi<0.113
+
 # CUDA-Q is installed separately on the Space (see README).