Regression testing: CPU and GPU kernel tests in CI

[ianna]

Description of new feature

@ManasviGoyal and @jpivarski : This issue is intended to help with keeping track of the tests run before introducing any new changes to the automated test framework. We have to assume that the number of the listed below tests that pass will be either increasing, or remain the same. The (minimal) test framework changes are intended to introduce the GPU tests.

The testing enabled by this PR gives the following results:

Run Tests (ubuntu-latest, 3.11, x64, full)
succeeded 12 hours ago in 4m 56s

• Test specification

====================== 6448 passed, 282 skipped in 19.08s ======================

• Test specifications with explicitly defined values

============================= 1578 passed in 2.70s =============================

• Test CPU kernels

====================== 6448 passed, 282 skipped in 24.56s ======================

• Test CPU kernels with explicitly defined values

============================ 4978 passed in 13.85s =============================

• test non-kernels 3m 15s

[ManasviGoyal]

#2938 adds 4978 CPU unit-tests