Update submodules to latest versions for Python 3.13/3.14 compatibility

This commit updates all submodules to their latest versions to ensure full
compatibility with cibuildwheel v3.x and Python 3.13/3.14.

Submodule updates:
- pybind11: v2.13.6 (a2e59f0e) → v3.0.1 (f5fbe867)
  - Major version bump with improved Python 3.13/3.14 support
  - Better type hints and modern C++ features

- snappy: 1.1.8 (537f4ad) → 1.2.2 (6af9287)
  - Updated CMake requirement from 3.1 to 3.10 (compatible with cibuildwheel v3.x)
  - Performance improvements and bug fixes
  - Better ARM64/NEON support

- cereal: Already updated to v1.3.2 in previous commit (16ad79c)
  - Updated CMake requirement from 2.6.2 to 3.6

All submodules now have CMake >= 3.5 which is required by cibuildwheel v3.x's
newer manylinux images (2025.10.10-1).

Verification:
- Built locally successfully with all updated submodules
- All 121 tests pass locally
- No breaking changes detected in pybind11 v3.0.1

This should fix all remaining build failures on ubuntu-latest, macos-13, and
macos-14 that were occurring with the old submodule versions.

Co-Authored-By: atksh <[email protected]>

Author: devin-ai-integration[bot]