Try use self hosted linux runner to build html and latexpdf to check for errors.
Trying to use the build artifact didn't seem to work, so just run it on its own.
Upload docs/build folder as artifact to enable review without having to build
locally. Note: doesn't include verific, so will differ slightly from final
published docs.
* `misc/__init__.py`:
* checks if there's a `yosys-abc` in the same directory - if yes, sets the variable `sys._pyosys_abc`
* checks if there's a `share` in the same directory - if yes, sets the variable `sys._pyosys_share_dirname`
* `yosys.cc::init_share_dirname`: check for `sys._pyosys_share_dirname`, use it at the highest priority if Python is enabled
* `yosys.cc::init_abc_executable_name`: check for `sys._pyosys_abc`, use it at at the highest priority if Python is enabled
* `Makefile`: add new target, `share`, to only create the extra targets
* `setup.py`: compile libyosys.so, yosys-abc and share, and copy them all as part of the pyosys build
* `test/arch/ecp5/add_sub.py`: ported `add_sub.ys` to Python to act as a test for the share directory and abc with Python wheels, used in CI
Since `docs/prep` is a prerequisite of `docs`, and should be the *only* prerequisite, calling `make docs` could end up hiding a problem with files missing from the uploaded artifact. Instead, call `make` from the docs directory which should be closer to what will run on RTDs.
* wheel versions now replace `+` with `.post` to match spec at https://packaging.python.org/en/latest/specifications/version-specifiers/
* CI updates:
* Bump action versions
* Disabled Windows for now and documented why
* Added a new job to upload all wheels
* Added new variable, `PYPI_INDEX`: fallback 'https://pypi.org/' if unset
* Added new secret, `PYPI_TOKEN`
* .editorconfig now uses 2 spaces for YML (it kept setting mine to tabs
and GitHub Actions doesn't like that)
