fix typo

Author: maxkahan

.github/workflows/ot.yml

@@ -21,7 +21,7 @@ jobs:
     runs-on: "ubuntu-24.04"
     strategy:
       matrix:
-        python-version: [3.8, 3.9, 3.10, 3.11, 3.12]
+        python-version: ['3.9', '3.10', '3.11', '3.12']
 
     steps:
     - uses: actions/checkout@v3