text: Title: [serve] proxy memory leak
  Body: ### What happened + What you expected to happen
  
  Seeing memory growth in the proxy actor over time indicating a memory leak:
  
  <img width="1357" alt="Image" src="https://github.com/user-attachments/assets/e0fd6e84-6e92-4e7c-91e2-4169ffc0bee2" />
  
  ### Versions / Dependencies
  
  Ray 2.41
  
  ### Reproduction script
  
  n/a
  
  ### Issue Severity
  
  None