push.yml: update the "checkout" action to v5

Author: stephengold

.github/workflows/push.yml

@@ -13,7 +13,7 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: 8
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - run: ./gradlew build install --console=plain --stacktrace
 
   Java11-Linux:
@@ -24,7 +24,7 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: 11
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: gradle/actions/wrapper-validation@v4
       - run: ./gradlew build install --console=plain --stacktrace
 
@@ -36,7 +36,7 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: 17
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - run: ./gradlew build install --console=plain --stacktrace
 
   Java24-Windows:
@@ -47,6 +47,6 @@ jobs:
         with:
           distribution: 'zulu'
           java-version: 24
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - run: ./gradlew build install --console=plain --stacktrace
         shell: bash