Actually, google-java-format works on java 17 and up

buildSrc/src/main/groovy/rhino.java-conventions.gradle

@@ -45,9 +45,9 @@ test {
 
 spotless {
     // There is no version of googleJavaFormat that works for Java 11 and 17,
-    // and different versions format differently. For now, only run spotless on Java 11.
-    // This will have to be changed when Java 11 support is removed.
-    if (JavaVersion.current() == JavaVersion.VERSION_21) {
+    // and different versions format differently. We're using a version that
+    // requires at least Java 17.
+    if (JavaVersion.current() >= JavaVersion.VERSION_17) {
         java {
             googleJavaFormat('1.23.0').aosp()
         }