Make dependency of _usmarray.pyx on *.pxi files explicit in cmake

[oleksandr-pavlyk]

"dpctl/tensor/_usmarray.pyx" includes several *.pxi files, but this dependency was not reflect in cmake script.

This PR addresses that oversight.

• 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?
• If this PR is a work in progress, are you filing the PR as a draft?

[github-actions]

View rendered docs @ https://intelpython.github.io/dpctl/pulls/1112/index.html

[coveralls]

Coverage: 82.404%. Remained the same when pulling 9da8978 on add-pxi-dependencies into 51863d4 on master.

[github-actions]

Array API standard conformance tests for dpctl=0.14.2=py310h76be34b_30 ran successfully.
Passed: 46
Failed: 788
Skipped: 280

[github-actions]

Deleted rendered PR docs from intelpython.github.com/dpctl, latest should be updated shortly. 🤞

[github-actions]

Array API standard conformance tests for dpctl=0.14.2=py310h76be34b_37 ran successfully.
Passed: 46
Failed: 788
Skipped: 280