chore: remove unused context

Author: kiendang

.github/workflows/tests.yml

@@ -30,8 +30,6 @@ jobs:
           pip install tox tox-gh-actions
       - name: Test with tox
         run: tox
-        env:
-          TOXENV: ${{ matrix.toxenv }}
 
   coverage:
     runs-on: ubuntu-latest