fix(lifespan): allow endpoints that don't support trailing slashes

e.g. OIDC_DISCOVERY_URL=https://accounts.google.com/.well-known/openid-configuration

Author: alukach

src/stac_auth_proxy/lifespan.py

@@ -40,12 +40,10 @@ async def check_server_health(
     if isinstance(url, HttpUrl):
         url = str(url)
 
-    async with httpx.AsyncClient(
-        base_url=url, timeout=timeout, follow_redirects=True
-    ) as client:
+    async with httpx.AsyncClient(timeout=timeout, follow_redirects=True) as client:
         for attempt in range(max_retries):
             try:
-                response = await client.get("/")
+                response = await client.get(url)
                 response.raise_for_status()
                 logger.info(f"Upstream API {url!r} is healthy")
                 return