How to create watertight mesh with Open3D ?

### Checklist

- [X] I have searched for [similar issues](https://github.com/isl-org/Open3D/issues).
- [X] For Python issues, I have tested with the [latest development wheel](http://www.open3d.org/docs/latest/getting_started.html#development-version-pip).
- [X] I have checked the [release documentation](http://www.open3d.org/docs/release/) and the [latest documentation](http://www.open3d.org/docs/latest/) (for `master` branch).

### My Question

@adamlofts @equant @benjaminum @FreakTheMighty @gsakkis Hello.

I use my extracted point clouds (in attached) to do create mesh and saved it as .obj file. You can find below the link to the mesh.
https://drive.google.com/file/d/1dPqnw84VP-L4GQFf6MYoAEHHEKTCfEoV/view?usp=share_link

But apparently to calculate volume (m³) of the object, I need to have a watertight mesh.
Can you please check on my object and let me know how I can make a watertight mesh with Open3D.
I look forward to hearing from you and thanks in advance!!!

[Laptop.txt](https://github.com/isl-org/Open3D/files/11486521/Laptop.txt)