Add mkl dependency

[ndgrigorian]

This PR proposes adding mkl to pyproject.toml as a runtime dependency, and mkl-devel as a build-system dependency. This aligns pyproject.toml with the meta.yaml.

Slips in change removing unneeded travis.yml

[Copilot]

Pull request overview

Aligns pyproject.toml dependency metadata with the conda recipe by declaring MKL-related dependencies, and removes legacy Travis CI configuration.

Changes:

• Add mkl-devel to build-system.requires in pyproject.toml.
• Add mkl to [project].dependencies in pyproject.toml.
• Remove the obsolete .travis.yml file.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
pyproject.toml	Adds MKL build/runtime dependencies to project metadata.
.travis.yml	Deletes legacy Travis CI configuration.

[antonwolfy]

Thank you @ndgrigorian
The only small nit from me is to populate the changelog