Download tarballs instead of Git repos for "3rdparty/uvatlas".

[quorten]

This style adjustment makes uvatlas more consistent with the specification style of all the other third-party dependencies. Most importantly, it makes it possible to compile Open3D inside of a chroot jail by simply unpacking the tarballs of all third-party dependencies into the same workspace.

Type

• Bug fix (non-breaking change which fixes an issue): Fixes #
• New feature (non-breaking change which adds functionality). Resolves #
• Breaking change (fix or feature that would cause existing functionality to not work as expected) Resolves #

Motivation and Context

Building Open3D within a non-networked chroot jail is unnecessarily complicated when a git shallow-clone needs to be packaged for delivery into the jail. This is fixed simply by specifying the tarball URL instead.

Checklist:

• I have run python util/check_style.py --apply to apply Open3D code style
  to my code.
• This PR changes Open3D behavior or adds new functionality.
  • Both C++ (Doxygen) and Python (Sphinx / Google style) documentation is
    updated accordingly.
  • I have added or updated C++ and / or Python unit tests OR included test
    results (e.g. screenshots or numbers) here.
• I will follow up and update the code if CI fails.
• For fork PRs, I have selected Allow edits from maintainers.

Description

[update-docs]

Thanks for submitting this pull request! The maintainers of this repository would appreciate if you could update the CHANGELOG.md based on your changes.