Actions: Upgrade to Java 20 including the steps actions/checkout@v2 t…

…o actions/checkout@v4, and actions/setup-java@v2 to actions/setup-java@v4

.github/workflows/scala.yml

@@ -7,22 +7,22 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 11
-      uses: actions/setup-java@v2
+    - uses: actions/checkout@v4
+    - name: Set up JDK 20
+      uses: actions/setup-java@v4
       with:
-        java-version: '11'
+        java-version: '20'
         distribution: 'adopt'
     - name: Run tests
       run: sbt test
   publish:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 11
-      uses: actions/setup-java@v2
+    - uses: actions/checkout@v4
+    - name: Set up JDK 20
+      uses: actions/setup-java@v4
       with:
-        java-version: '11'
+        java-version: '20'
         distribution: 'adopt'
     - name: Publish package
       run: sbt test publish