fix: Disable active_timer When registry_ttl_sec is 0 (feast-dev#4499)

* fix: Disable active_timer When registry_ttl_sec is 0

Signed-off-by: Jiwon Park <phil.park@sktelecom.com>

* feat: Add delete mark

Signed-off-by: Jiwon Park <phil.park@sktelecom.com>

---------

Signed-off-by: Jiwon Park <phil.park@sktelecom.com>

Author: jparkzz

sdk/python/feast/feature_server.py

@@ -90,9 +90,11 @@ def async_refresh():
         registry_proto = store.registry.proto()
         if shutting_down:
             return
-        nonlocal active_timer
-        active_timer = threading.Timer(registry_ttl_sec, async_refresh)
-        active_timer.start()
+
+        if registry_ttl_sec:
+            nonlocal active_timer
+            active_timer = threading.Timer(registry_ttl_sec, async_refresh)
+            active_timer.start()
 
     @asynccontextmanager
     async def lifespan(app: FastAPI):