Fix Python CI dependency installation

[aadilghani1]

The Python 3.10 and 3.12 CI jobs fail during test collection because the workflow installs only pushary and pytest, then installs the adapter with --no-deps. This skips its declared Pydantic/LangGraph dependencies and the SQLite checkpoint test extra.

Install the editable package with .[test] and pytest, run pip check, and invoke pytest through the selected Python interpreter. The package already declares the correct dependencies, so this changes only the mirror-owned workflow; no runtime or monorepo source change is needed.

Validation:

• Reproduced the existing ModuleNotFoundError failures for pydantic and langgraph in a fresh Python 3.12 environment.
• Corrected install on Python 3.10 and 3.12: pip check passes; all 14 tests and 6 subtests pass on each version, including SQLite checkpoint restart tests.
• git diff --check passes.

Fixes the dependency setup failures in runs 34633325152 and 34629358425.