Persist venv across job steps

.github/workflows/build_env_run_tests.yml

@@ -35,20 +35,21 @@ jobs:
           pip install -e .[dev]
           pip list
           python -c "import aeon"
-
+      - name: Activate venv for later steps
+        run: |
+          echo "VIRTUAL_ENV=$(pwd)/.venv" >> $GITHUB_ENV
+          echo "$(pwd)/.venv/bin" >> $GITHUB_PATH      # For Unix-like systems
+          echo "$(pwd)/.venv/Scripts" >> $GITHUB_PATH  # For Windows
       # Only run codebase checks and tests for Linux (ubuntu).
       - name: ruff
         if: matrix.os == 'ubuntu-latest'
-        run: python -m ruff check .
-
+        run: ruff check .
       - name: pyright
         if: matrix.os == 'ubuntu-latest'
         run: python -m pyright --level error --project ./pyproject.toml . 
-
       - name: pytest
         if: matrix.os == 'ubuntu-latest'
         run: python -m pytest tests/ --ignore=tests/dj_pipeline
-
       - name: generate test coverage report
         if: ${{ matrix.os == 'ubuntu-latest' }}
         run: |