fix: remove stale Python 3.10 TODOs and fix typo in pyproject.toml

[Arijit Kumar Roy (arijitroy003)]

Summary

• Fix typo in pyproject.toml line 77: 'takemore' should be 'take more'
• Remove stale TODO comments in langchain_postgres/v2/vectorstores.py and langchain_postgres/v2/async_vectorstore.py that say to remove from __future__ import annotations when min Python is 3.10 — but requires-python is already >=3.10

Testing

Typo fix and TODO cleanup only. The from __future__ import annotations import is kept as it is still useful for forward references.