Support Mac build, update GHA build to take into account latest Surelog compatibility changes, remove conda

[timkpaine]

Opening this for visibility, please don't "Approve and Run" the CI as I will continue to be noisy. I am testing actions on my fork.

• Support MacOS - Fixes macOS: There's no -D switch in BSD install #74
• Install Surelog / UHDM in normal manner, remove bespoke conda channel dependency
  • pins Surelog in CI, easily updatable manner
• Aligns with yosys-0.17 to match conda version, sets up for easier upgrading in CI
  • renames synth_quicklogic to synth_quicklogic_f4pga (fixes synth_quicklogic name conflict #496)
  • pins version of pmgen (not a fix for, but related to pmgen.py is downloaded without checking the cryptographic hash #526)
• Port from unsupported json11 to nlohmann-json (nlohmann-json also used by Surelog as of Issue#3812#3818 Introducing json, and cache working directories for sepcmd Surelog#3827, so this is a good alignment)

This PR has been validated locally against a non-conda Surelog / UHDM and source-installed Yosys on MacOS 13, but is still very much a work-in-progress as I work through lots of CI changes

xref / supercedes: #445
xref: #431
xref: #432
xref: #365

[hzeller]

Aren't there googletest dependencies available in Ubuntu and homebrew that we can use directly from the package manager ?

That way we don't need the separate googletest compilation step below.

[timkpaine]

I'm not sure if they compile to support c++ 17 string views which are needed, I can test though

[hzeller]

I think removing the gtest from third_party and then use what is on the system is a good improvement that can be done in a smallish, separate PR and reduces the size of this one.

[hzeller]

Should the workflow be run ?
Did you have time to break out the "don't use gtest from third_party/ but always in system" change ?

[timkpaine]

sorry will be getting back to this shortly, been a busy couple months 😢

[timkpaine]

This PR is ready, please do NOT enable the workflows yet as there appears to be a new (~1-2 days ago) issue with homebrew ccache that I want to resolve on my fork before making extra noise for everyone.

Given the size of this PR, even though the complexity is quite low, I've started breaking changes out into other PRs:

• Upgrade GitHub actions with deprecation warnings #544
• Rename synth_quicklogic to synth_quicklogic_f4pga to not conflict with yosys builtin #543

There are a few major follow-on issues to investigate:

• this repo pinned yosys to 0.17 via a custom conda channel. We now pull direct from the repo (we could also pull from conda-forge, where yosys is now also available), but I left the version at 0.17 which is quite old now. This should be upgraded to the latest version if possible
• enable similar changes on https://github.com/chipsalliance/systemverilog-plugin ?
• package for various distribution channels (I will do homebrew and conda-forge)

[timkpaine]

Everything except the linux ql-qlf plugin is working and passing all tests.

I believe this is due to little differences is path handling, I hit a bunch of those for e.g. how icarus deals with include paths, etc.

All conda reliance is completely removed.
I also have to rebase after #546

If possible id like to get #543 and #544 in first