Release: Numpy 2 Followup + Drop Python 3.7

[mikedh]

• Numpy 2 wasn't being tested in docker
  • fixes tests/test_gltf.py::GLTFTest::test_vertex_colors_import fails with NumPy 2.0.0rc2 #2237
  • Replaces deprecated 2D use of np.cross
• This release was blocked by mysterious build failures in trimesh/vhacdx. Eventually got this to pass but there were bugs on Python 3.7/windows that are probably possible for someone to debug, but that person isn't me.
  • I don't love depreciating Python versions but 3.7 has been EOL for more than a year, and I think there is probably some subtle upstream thing that is not worth blocking releases any further over.
• allow more functions to work with (n, 2) vertices in addition to (n, 3) vertices, including:
  • trimesh.triangles: points_to_barycentric, barycentric_to_points
  • trimesh.path: Path3D.to_planar
• add a precise option on Trimesh.projected which just does the slow-but-correct unary union of all the triangles.
• add an option to use manifold3d.triangulate pretty much interchangeably with triangle and mapbox_earcut.
  • promotes manifold3d to easy install both since manifold is sweet and mapbox_earcut on numpy 2.0 needs this PR to work.
  • Some benchmarks of the triangulation options indicate that earcut is the fastest option by a quite wide margin, although I would imagine triangle and manifold have different levels of robust behavior.
• releases FIX #2245: perform the same input validations as in intersects_id #2246 which fixes ray_pyembree: intersects_location and intersects_any yielding different outputs #2245
• release Changed boolean_manifold iteration for improved performance. #2249 which performs a pairwise reduce rather than an incrementing reduce