Disable flask and quart debug (#14042)

### What problem does this PR solve?

Visit
`http://127.0.0.1:9381/?__debugger__=yes&cmd=resource&f=debugger.js`
will expose the flask code:
```
docReady(() => {
  if (!EVALEX_TRUSTED) {
    initPinBox();
  }
  // if we are in console mode, show the console.
  if (CONSOLE_MODE && EVALEX) {
    createInteractiveConsole();
  }

  const frames = document.querySelectorAll("div.traceback div.frame");
  if (EVALEX) {
    addConsoleIconToFrames(frames);
  }
  addEventListenersToElements(document.querySelectorAll("div.detail"), "click", () =>
    document.querySelector("div.traceback").scrollIntoView(false)
  );
  addToggleFrameTraceback(frames);
  addToggleTraceTypesOnClick(document.querySelectorAll("h2.traceback"));
  addInfoPrompt(document.querySelectorAll("span.nojavascript"));
  wrapPlainTraceback();
});

function addToggleFrameTraceback(frames) {
  frames.forEach((frame) => {
    frame.addEventListener("click", () => {
      frame.getElementsByTagName("pre")[0].parentElement.classList.toggle("expanded");
    });
  })
}

```

### Type of change

- [x] Other (please describe): Fix security risk

admin/server/admin_server.py

@@ -21,7 +21,6 @@ import os
 import signal
 import logging
 import threading
-import traceback
 import faulthandler
 
 from flask import Flask
@@ -75,10 +74,10 @@ if __name__ == '__main__':
             application=app,
             threaded=True,
             use_reloader=False,
-            use_debugger=True,
+            use_debugger=False,
         )
-    except Exception:
-        traceback.print_exc()
+    except Exception as e:
+        logging.exception(f"Unhandled exception: {e}")
         stop_event.set()
         time.sleep(1)
         os.kill(os.getpid(), signal.SIGKILL)