Simplify iteration space as static library

[oleksandr-pavlyk]

The "simplify_iteration_space.cpp" was being compiled as source for every pybind11 native extension.

This change compiles it as a static library once, and links the library into pybind11 native extension modules, shaving some build time.

"simplify_iteration_space.cpp" also no longer includes "dpctl4pybind11.hpp", and hence does not need SYCL target enabled, compiling it as ordinary host code.

---

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[oleksandr-pavlyk]

On rather beefy server, the build time improved very slightly, as reported by /usr/bin/time -f "%P %E %M" python scripts/build_locally.py --verbose:

branch	CPU utilization	Wall-time	Peak memory usage
PR branch	1154%	5:32.50	3974668
main branch	1134%	5:42.66	3980596

[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=py310hdf72452_66 ran successfully.
Passed: 894
Failed: 1
Skipped: 119

[github-actions]

Array API standard conformance tests for dpctl=0.19.0dev0=py310hdf72452_67 ran successfully.
Passed: 894
Failed: 1
Skipped: 119

[coveralls]

coverage: 87.907%. remained the same
when pulling 3f6af83 on simplify-iteration-space-as-static-library
into 687d66f on master.

[ndgrigorian]

Tested changes locally and it works fine. Extensions which leverage simplify_iteration_space also build correctly.

LGTM!

[oleksandr-pavlyk]

Compiled for CUDA target. The test suite run was a PASS.