chore: migrate package name to letta (#1775)

Co-authored-by: Charles Packer <packercharles@gmail.com>
Co-authored-by: Shubham Naik <shubham.naik10@gmail.com>
Co-authored-by: Shubham Naik <shub@memgpt.ai>

.github/workflows/test_openai.yml

@@ -28,7 +28,7 @@ jobs:
       env:
         OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
       run: |
-        poetry run memgpt quickstart --backend openai
+        poetry run letta quickstart --backend openai
 
     - name: Test LLM endpoint
       env: