chore: format Python version list in CI workflow for improved readability

Author: ya7010

.github/workflows/ci.yml

@@ -11,7 +11,10 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.11.0', '3.12.0', '3.13.0']
+        python-version:
+          - '3.11.0'
+          - '3.12.0'
+          - '3.13.0'
 
     steps:
     - uses: actions/checkout@v4