Drop 2020 and below

Author: zepinglee

.github/tl_packages_2019

@@ -51,24 +51,16 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: [2025, 2024, 2023, 2022, 2021, 2020, 2019]
+        version: [2025, 2024, 2023, 2022, 2021]
     steps:
       - name: Checkout
         uses: actions/checkout@v6
 
       - name: Set up TeX Live ${{ matrix.version }}
-        if: ${{ matrix.version >= 2021 }}
         uses: TeX-Live/setup-texlive-action@v3
         with:
           version: ${{ matrix.version }}
           package-file: .github/tl_packages
-
-      - name: Set up TeX Live ${{ matrix.version }}
-        if: ${{ matrix.version < 2021 }}
-        uses: TeX-Live/setup-texlive-action@v3
-        with:
-          version: ${{ matrix.version }}
-          package-file: .github/tl_packages_${{ matrix.version }}
         # uses: zauguin/install-texlive@v4
         # with:
         #   texlive_version: ${{ matrix.version }}