Update Github actions to more recent versions.

Author: craigthomas

.github/workflows/gradle.yml

@@ -2,14 +2,14 @@ name: Build Test Coverage
 on: [push, pull_request]
 jobs:
   run:
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu:latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v3
-    - name: Setup JDK 11
-      uses: actions/setup-java@v3
+      uses: actions/checkout@v6
+    - name: Setup JDK 17
+      uses: actions/setup-java@v5
       with:
-        java-version: '11'
+        java-version: '17'
         distribution: 'adopt'
     - name: Install xvfb for headless testing
       run: sudo apt-get install xvfb
@@ -18,6 +18,6 @@ jobs:
     - name: Build with Gradle
       run: xvfb-run --auto-servernum ./gradlew build
     - name: Codecov
-      uses: codecov/codecov-action@v4.2.0
+      uses: codecov/codecov-action@v5
       env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}