Make explicit the location for the `CMakeUserPresets.json` file.
Update docs tests documentation.
Move `BUILD_DIR` and `PROGRAM_PREFIX` comments into the functional tests todo.
Add cmake to MacPorts/FreeBSD install instructions.
Add ccache to example `CMakeUserPresets.json` (it isn't otherwise documented, and is no longer as obvious without an `ENABLE_CCACHE` makevar).
Addressing comments
This commit reimplements the (no longer recommended) setuptools based
build system using a standards-based in-tree PEP517 build backend.
The implementation is partially based on
https://codeberg.org/ziglang/zig-pypi/src/branch/main/make_wheels.py
which is licensed under BSD-0-clause.
It also adds a new option `YOSYS_BUILD_PYTHON_ONLY` that is available
only if the binary or the library aren't going to be installed, which
turns off these targets entirely, as well as some dependent ones
(e.g. tests).
Co-authored-by: Mohamed Gaber <me@donn.website>