Reverting max-parallel limit as it didn't fix the hangs

Author: jsa34

.github/workflows/main.yml

@@ -35,7 +35,6 @@ jobs:
             toxfactor: py3.13
             ignore-typecheck-outcome: false
             ignore-test-outcome: false
-      max-parallel: 1
 
     steps:
     - uses: actions/checkout@v3