chore: use starlette built-in Route class (#2267)

# What does this PR do?

Use a more common pattern and known terminology from the ecosystem,
where Route is more approved than Endpoint.

Signed-off-by: Sébastien Han <seb@redhat.com>

requirements.txt

@@ -1,5 +1,11 @@
 # This file was autogenerated by uv via the following command:
 #    uv export --frozen --no-hashes --no-emit-project --no-default-groups --output-file=requirements.txt
+aiohappyeyeballs==2.5.0
+    # via aiohttp
+aiohttp==3.11.13
+    # via llama-stack
+aiosignal==1.3.2
+    # via aiohttp
 annotated-types==0.7.0
     # via pydantic
 anyio==4.8.0
@@ -7,8 +13,12 @@ anyio==4.8.0
     #   httpx
     #   llama-stack-client
     #   openai
+    #   starlette
+async-timeout==5.0.1 ; python_full_version < '3.11'
+    # via aiohttp
 attrs==25.1.0
     # via
+    #   aiohttp
     #   jsonschema
     #   referencing
 certifi==2025.1.31
@@ -36,6 +46,10 @@ filelock==3.17.0
     # via huggingface-hub
 fire==0.7.0
     # via llama-stack
+frozenlist==1.5.0
+    # via
+    #   aiohttp
+    #   aiosignal
 fsspec==2024.12.0
     # via huggingface-hub
 h11==0.16.0
@@ -56,6 +70,7 @@ idna==3.10
     #   anyio
     #   httpx
     #   requests
+    #   yarl
 jinja2==3.1.6
     # via llama-stack
 jiter==0.8.2
@@ -72,6 +87,10 @@ markupsafe==3.0.2
     # via jinja2
 mdurl==0.1.2
     # via markdown-it-py
+multidict==6.1.0
+    # via
+    #   aiohttp
+    #   yarl
 numpy==2.2.3
     # via pandas
 openai==1.71.0
@@ -86,6 +105,10 @@ prompt-toolkit==3.0.50
     # via
     #   llama-stack
     #   llama-stack-client
+propcache==0.3.0
+    # via
+    #   aiohttp
+    #   yarl
 pyaml==25.1.0
     # via llama-stack-client
 pyasn1==0.4.8
@@ -145,6 +168,8 @@ sniffio==1.3.1
     #   anyio
     #   llama-stack-client
     #   openai
+starlette==0.45.3
+    # via llama-stack
 termcolor==2.5.0
     # via
     #   fire
@@ -162,6 +187,7 @@ typing-extensions==4.12.2
     #   anyio
     #   huggingface-hub
     #   llama-stack-client
+    #   multidict
     #   openai
     #   pydantic
     #   pydantic-core
@@ -173,3 +199,5 @@ urllib3==2.3.0
     # via requests
 wcwidth==0.2.13
     # via prompt-toolkit
+yarl==1.18.3
+    # via aiohttp