Use JDK 17 Since 6.5.x Kotlin Does not Support JDK 25

Using JDK 25 a full build fails with

```
e: java.lang.IllegalArgumentException: 25.0.2
	at org.jetbrains.kotlin.com.intellij.util.lang.JavaVersion.parse(JavaVersion.java:307)
	at org.jetbrains.kotlin.com.intellij.util.lang.JavaVersion.current(JavaVersion.java:176)
	at org.jetbrains.kotlin.cli.jvm.modules.JavaVersionUtilsKt.isAtLeastJava9(javaVersionUtils.kt:11)
	at org.jetbrains.kotlin.cli.jvm.modules.CoreJrtFileSystem.globalJrtFsCache$lambda$2(CoreJrtFileSystem.kt:8
```

Signed-off-by: Rob Winch <362503+rwinch@users.noreply.github.com>

.github/workflows/deploy-docs.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Set Up Gradle
       uses: spring-io/spring-gradle-build-action@v2
       with:
-        java-version: '25'
+        java-version: '17'
         distribution: temurin
     - name: Set up refname build
       if: github.event.inputs.build-refname