Update required JAVA_HOME variables for running tests (#80145)

I believe ES gets tested now against only JDK 8, 11, and 17, so you would need to have only `JAVA8_HOME`, `JAVA11_HOME`, and `JAVA17_HOME` set up in order to run the tests locally.

CONTRIBUTING.md

@@ -120,8 +120,7 @@ JDK 16 and testing on a JDK 11 runtime; to do this, set `RUNTIME_JAVA_HOME`
 pointing to the Java home of a JDK 11 installation. Note that this mechanism can
 be used to test against other JDKs as well, this is not only limited to JDK 11.
 
-> Note: It is also required to have `JAVA8_HOME`, `JAVA9_HOME`, `JAVA10_HOME`
-and `JAVA11_HOME`, `JAVA12_HOME`, `JAVA13_HOME`, `JAVA14_HOME`, and `JAVA15_HOME`
+> Note: It is also required to have `JAVA8_HOME`, `JAVA11_HOME`, and `JAVA17_HOME`
 available so that the tests can pass.
 
 Elasticsearch uses the Gradle wrapper for its build. You can execute Gradle