Drop direct build dependency on `meson` and `ninja`

[arcondello]

See mesonbuild/meson#15953 (comment)

[arcondello]

I'll have to dig into what "new enough" means. If for instance we require a feature that's only available in meson 1.11.x, do we have some mechanism to enforce that with the meson-python install? I'll RTFM.

[arcondello]

Ok, looks like meson-python always installs meson

  'meson >= 0.64.0; python_version < "3.12"',
  'meson >= 1.2.3; python_version >= "3.12"',

https://github.com/mesonbuild/meson-python/blob/e33fe06294364cda041d1a45e9da0b96f415ae3e/pyproject.toml#L37-L38

so I think we should drop ninja but specify the minimum meson version that we need.