fix(python): standardize Python version across all packages

- Updated all `libs/python/*/pyproject.toml` files to require Python >=3.12
- Synchronized root `pyproject.toml` and regenerated `uv.lock`

libs/python/computer-server/pyproject.toml

@@ -12,7 +12,7 @@ authors = [
 ]
 readme = "README.md"
 license = { text = "MIT" }
-requires-python = ">=3.9"
+requires-python = ">=3.12"
 dependencies = [
     "fastapi>=0.111.0",
     "uvicorn[standard]>=0.27.0",