[Bug]: An agent memory can be shared multiple times

[Ripcord55]

Describe the bug

When utilizing the API to implement the share function of Agent memory, the same Agent memory can be shared multiple times

Environment

0.3.0

Fast reproduce steps

Perform the operation of sharing agent memory multiple times：

time curl -X POST "http://localhost:8001/api/v1/agents/agent-456/memories/share" \
  -H "X-API-Key: key1" \
  -H "Content-Type: application/json" \
  -d '{
    "target_agent_id": "agent-789"
  }'

Expected behavior

No response

Actual behavior

No response

Additional context

No response