fix: use macos-12 instead of macos-latest in CI

[antazoey]

What I did

The following issue seems to block python3.8-3.9 for macos arm: actions/setup-python#808

NOTE: Anticipating things may still fail because of gacts/install-geth action

How I did it

How to verify it

Checklist

• All changes are completed
• New test cases have been added
• Documentation has been updated

[wakamex]

this user suggests getting rid of the setup-python action, in favor of manually installing python and pip (though i'd suggest uv pip). it seems to work for macos-13 as well. actions/setup-python#696 (comment)

[antazoey]

actions/setup-python#696 (comment)

We would have to separate mac-os from ubuntu more if we went this route. We have test.yml able to run on both, with the OS being in a matrix.

[antazoey]

this user suggests getting rid of the setup-python action, in favor of manually installing python and pip (though i'd suggest uv pip). it seems to work for macos-13 as well. actions/setup-python#696 (comment)

because of the refactor required and my optimism 808 will be resolved, I want to stick to having macos in the matrix and using setup-pyhon... but will wait until for more thoughts before merging this.

[wakamex]

you could get rid of setup-python entirely with a step like this (not saying this is the way to go, just an option, maybe if the action keeps giving you problems):

      - name: Install dependencies
        run: |
          if [ "$RUNNER_OS" == "Linux" ]; then
            apt update
            apt install -y python${{ matrix.python-version }}
          elif [ "$RUNNER_OS" == "macOS" ]; then
            brew update
            brew install python@${{ matrix.python-version }}
          fi

[antazoey]

run: |
if [ "$RUNNER_OS" == "Linux" ]; then
apt update
apt install -y python${{ matrix.python-version }}
elif [ "$RUNNER_OS" == "macOS" ]; then
brew update
brew install python@${{ matrix.python-version }}
fi

eventually would also add windows here.

[antazoey]

it feels like we are re-inventing wha setup-python is supposed to do... setup-python should be fixed, that seems like fixing it in the right spot.

edit: we can adjust to @wakamex 's workaround after further discussion. For now, am going with this.