Fix incorrect results from cumulative_sum and cumulative_prod with dtype=bool

[ndgrigorian]

This PR resolves gh-2017 by introducing missing dedicated kernels for bool->bool in the type matrix of cumulative_sum and cumulative_prod.

Also slips in the addition of int8->int8

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

[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=0.19.0dev0=py310h93fe807_550 ran successfully.
Passed: 895
Failed: 1
Skipped: 118

[coveralls]

coverage: 88.138% (-0.1%) from 88.233%
when pulling fa525a7 on resolve-gh-2017
into 5e1c87d on master.

[github-actions]

Array API standard conformance tests for dpctl=0.20.0dev0=py310h93fe807_4 ran successfully.
Passed: 892
Failed: 4
Skipped: 118

[github-actions]

Array API standard conformance tests for dpctl=0.20.0dev0=py310h93fe807_9 ran successfully.
Passed: 894
Failed: 2
Skipped: 118

[antonwolfy]

Looks good for me, thank you @ndgrigorian

[github-actions]

Array API standard conformance tests for dpctl=0.20.0dev0=py310h93fe807_10 ran successfully.
Passed: 895
Failed: 2
Skipped: 125

[antonwolfy]

LGTM! Thank you @ndgrigorian