Bump toolchains

[jngrad]

Description of changes:

• require Boost >= 1.81, CMake >= 3.27.6, Cython >= 3.0.8
• replace the Make build system by the Ninja build system

[jngrad]

Debian Trixie is currently in soft freeze, which means no further change can be made to toolchain packages, such as GCC, Clang, Python, CMake, Makefile, Ninja, binutils, and shell interpreters. OpenMPI, Boost and Cython have 1 pending trivial patch (NumPy 2 support backport). Trixie will reach hard freeze next week:
https://release.debian.org/trixie/freeze_policy.html

I think we don't risk much by deploying Debian Trixie now, and I can manually regenerate the Docker image once Trixie enters full freeze without altering the image identifier. Debian is used in GitHub Actions, not in GitLab-CI, therefore any unforeseen security issue won't affect our internal infrastructure. Getting Trixie in CI allows us to remove Boost patches, drop support for Cython 0.29, and drop support for CMake 3.25.1 (nvcc C++20 support comes with 3.25.2).

[hidekb]

LGTM