Reworks workflows into script (#661)

* Reworks some workflows to run a script instead

Advantages are:
- Only one set of tests needs maintenance.
- Local results match workflows, no surprises.
- Reduced reliance on GitHub actions.

Fixes #50, #168, #169, #171, #507

* Adds macos to the test matrix

.github/workflows/reproducible.yml

@@ -20,9 +20,7 @@ jobs:
         run: rustup show
       - uses: actions/setup-python@v1
         with:
-          python-version: 3.7
-      - name: Install Python dependencies
-        run: python -m pip install --upgrade pip setuptools wheel
+          python-version: "3.10"
       - name: Set up OpenSK
         run: ./setup.sh