Update CHANGELOG for dpnp.linalg.lu_factor

[vlad-perevezentsev]

This PR updates changelog by adding entries for dpnp.linalg.lu_factor.

• Have you provided a meaningful PR description?
• Have you added a test, reproducer or referred to an issue with a reproducer?
• Have you tested your changes locally for CPU and GPU devices?
• Have you made sure that new changes do not introduce compiler warnings?
• Have you checked performance impact of proposed changes?
• Have you added documentation for your changes, if necessary?
• Have you added your changes to the changelog?

[github-actions]

View rendered docs @ https://intelpython.github.io/dpnp/index.html

[github-actions]

Array API standard conformance tests for dpnp=0.19.0dev3=py313h509198e_20 ran successfully.
Passed: 1227
Failed: 0
Skipped: 9

[coveralls]

coverage: 72.19%. remained the same
when pulling 1ec181a on changelog_lu_factor
into f2b7d76 on master.