fix: Google embeddings endpoint bug (#2416)

[tarunkumark]

Please describe the purpose of this pull request.
This is a fix for the archival tools not working when using Google Gemini's embedding models - text-embedding-004 and embedding-001. Also fixed a few syntax errors in tests/test_base_function and tests/test_sdk_client that did not let me run pytest.

How to test
Command to run the test: poetry run pytest tests/test_google_embeddings
There are 3 test cases,

• checks validity of the gemini api endpoint
• an archival insert and retrieval for the text-embedding-004 embedding model
• an archival insert and retrieval for the embedding-001 embedding model

Have you tested this PR?
Pytest

PS E:\projects\open_source\letta> poetry run pytest .\tests\test_google_embeddings.py
================================================= test session starts =================================================
platform win32 -- Python 3.11.0, pytest-8.3.4, pluggy-1.5.0
rootdir: E:\projects\open_source\letta\tests
configfile: pytest.ini
plugins: anyio-4.8.0, langsmith-0.3.6, asyncio-0.23.8, mock-3.14.0, order-1.3.0
asyncio: mode=Mode.AUTO
collected 3 items

tests\test_google_embeddings.py ... 
====================================== 3 passed, 14 warnings in 87.65s (0:01:27) ======================================

text-embedding-004 archival output

embedding-001 archival output

Related issues or PRs
This is a fix intended for this issue #2416)

Is your PR over 500 lines of code?
No, 194 additions and 4 deletions.

Additional context
Add any other context or screenshots about the PR here.