prod: enable parallel testing for faster tests and fix codespeed deprecation

.github/workflows/benchmarks.yaml

@@ -42,4 +42,4 @@ jobs:
         with:
           token: ${{ secrets.CODSPEED_TOKEN }}
           run: pytest -vvs --codspeed
-          mode: instrumentation
+          mode: simulation

.github/workflows/python_package.yaml

@@ -37,14 +37,14 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          python -m pip install pytest pytest-codspeed pytest-randomly
+          python -m pip install pytest pytest-codspeed pytest-randomly pytest-xdist
           python -m pip install .
           # temp pin until 0.5 is on conda
           python -m pip install "jax<0.5.0"
 
       - name: Test with pytest
         run: |
-          pytest -vv --durations=100 --randomly-seed=42
+          pytest -n 2 -v --durations=100 --randomly-seed=42
 
   build-status:
     needs: build