Revert "Update Gradle to enable Java 21+ syntax on test code (do not affect production-code backward compatibility)"

This reverts commit 76bcbb1.

Author: tsantalis

.github/workflows/benchmark.yml

@@ -15,10 +15,10 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Set up JDK 21
+      - name: Set up JDK 17
         uses: actions/setup-java@v4
         with:
-          java-version: '21'
+          java-version: '17'
           distribution: 'temurin'
 
       - name: Checkout code

.github/workflows/gradle.yml

@@ -27,10 +27,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - name: Set up JDK 21
+    - name: Set up JDK 17
       uses: actions/setup-java@v4
       with:
-        java-version: '21'
+        java-version: '17'
         distribution: 'temurin'
 
     # Configure Gradle for optimal use in GiHub Actions, including caching of downloaded dependencies.

.github/workflows/updateTestStats.yml

@@ -19,10 +19,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
-    - name: Set up JDK 21
+    - name: Set up JDK 17
       uses: actions/setup-java@v4
       with:
-        java-version: '21'
+        java-version: '17'
         distribution: 'temurin'
 
     # Configure Gradle for optimal use in GiHub Actions, including caching of downloaded dependencies.

gradle/wrapper/gradle-wrapper.jar

@@ -1,7 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.14-bin.zip
-networkTimeout=10000
-validateDistributionUrl=true
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists