Update github workflow actions

Author: rbygrave

.github/workflows/build.yml

@@ -16,14 +16,14 @@ jobs:
         os: [ubuntu-latest]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up Java
-      uses: actions/setup-java@v2
+      uses: actions/setup-java@v4
       with:
         java-version: ${{ matrix.java_version }}
         distribution: 'zulu'
     - name: Maven cache
-      uses: actions/cache@v2
+      uses: actions/cache@v4
       env:
         cache-name: maven-cache
       with: