Update: github workflow

.github/workflows/main.yml

@@ -8,31 +8,31 @@ on:
 
 jobs:
   build:
-    # On Ubuntu 20.04
-    runs-on: ubuntu-20.04
+    # On Ubuntu 22.04
+    runs-on: ubuntu-22.04
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
 
-    - name: Set up Python 3.8
-      uses: actions/setup-python@v2
+    - name: Set up Python
+      uses: actions/setup-python@v5
       with:
-        python-version: 3.8
+        python-version: '3.8'
 
     - name: Install Dependencies
       run: |
-        pip3 install nml
+        pip install nml
 
     - name: Build NewGRF
       run: make all
 
     - name: Set variables
       id: vars
-      run: echo "::set-output name=sha_short::$(git rev-parse --short HEAD 2>/dev/null)"
+      run: echo "sha_short=$(git rev-parse --short HEAD 2>/dev/null)" >> $GITHUB_OUTPUT
 
     - name: Upload artifacts
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: Korean_Train_Set_${{ steps.vars.outputs.sha_short }}  # Name with sha short hash
         path: generated/Korean_Train_Set*.tar