chore(mypy): add mypy and type stub packages to dev deps (#3930)

## Summary

This PR adds mypy and essential type stub packages to dev dependencies
as Phase 1 of the mypy suppression removal plan.

**Changes:**
- Add `mypy` to dev dependencies
- Add type stubs: `types-jsonschema`, `pandas-stubs`, `types-psutil`,
`types-tqdm`, `boto3-stubs`

**Impact:**
- Enables static type checking across the codebase
- Eliminates ~30 type checking errors related to missing type
information for third-party packages
- Provides foundation for subsequent PRs to remove type suppressions

**Part of:** Mypy suppression removal plan (Phase 1/4)

**Testing:**
```bash
uv sync --group dev
uv run mypy
```

pyproject.toml

@@ -71,8 +71,14 @@ dev = [
     "nbval",               # For notebook testing
     "black",
     "ruff",
+    "mypy",
     "types-requests",
     "types-setuptools",
+    "types-jsonschema",
+    "pandas-stubs",
+    "types-psutil",
+    "types-tqdm",
+    "boto3-stubs",
     "pre-commit",
     "ruamel.yaml",         # needed for openapi generator
 ]