Install CIRCT out of Conda

[abejgonzalez]

The CIRCT community has some scripts to help install updated versions / update versions of CIRCT in repos. This PR is to see how well this works in Chipyard. There are two potential implementations of using these scripts:

1. This PR. I.e. handle CIRCT installation/updating separate from Conda. Allows us to remove the conda-feedstock for CIRCT and have less things inside of Conda (environment bloat).
2. Update the conda-feedstock to automatically update and publish using these scripts. I.e. the conda-feedstock will download CIRCT, put it in the conda location, and publish it. This will keep the same type of flow as before (all in conda) and will just require us to update firtool ourselves (maybe we can write a script to autoupdate it).

EDIT: We decided on #1 since it's shifts the burden of us having to maintain a feedstock to the CIRCT devs who already publish a working version of CIRCT.

Any thoughts?

Side Update: Moves the env.sh generation into the conda setup part of build-setup.sh. Thus if a later part of the flow fails you still have a env.sh to diagnose and manually do other parts of the setup.

Related PRs / Issues:

Type of change:

• Bug fix
• New feature
• Other enhancement

Impact:

• RTL change
• Software change (RISC-V software)
• Build system change
• Other

Contributor Checklist:

• Did you set main as the base branch?
• Is this PR's title suitable for inclusion in the changelog and have you added a changelog:<topic> label?
• Did you state the type-of-change/impact?
• Did you delete any extraneous prints/debugging code?
• Did you mark the PR with a changelog: label?
• (If applicable) Did you update the conda .conda-lock.yml file if you updated the conda requirements file?
• (If applicable) Did you add documentation for the feature?
• (If applicable) Did you add a test demonstrating the PR?

• (If applicable) Did you mark the PR as Please Backport?

[seldridge]

I'm glad to see these GitHub actions getting some use. I'm also glad that the factoring of circt/install-circt to be predominantly shell-based is working for you. If I ever find some time, I plan to convert circt/update-circt to also be similarly shell-based.

These things should be usable by flows which aren't GitHub Actions, i.e.

[jerryz123]

Can we move this submodule to tools? Since the install-circt stuff can be run in a non-conda environment.

[jerryz123]

Since the CIRCT stuff is not conda-specific, I think it can be outside of the conda directory.