Test with other versions of TeX Live

Author: zepinglee

.github/workflows/test.yml

@@ -51,7 +51,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [2025, 2024, 2023, 2022, 2021]
+        version: [2025, 2024, 2023, 2022, 2021, 2020, 2019]
     steps:
       - name: Checkout
         uses: actions/checkout@v6