Oracle JDK 21 support (#538)

* Allow Oracle JDK 21 usage

* Fix tests

* Add Java 21 support in the documentation

---------

Co-authored-by: Ivan Zosimov <[email protected]>

Author: jdubois

__tests__/distributors/oracle-installer.test.ts

@@ -22,6 +22,11 @@ describe('findPackageForDownload', () => {
   });
 
   it.each([
+    [
+      '21',
+      '21',
+      'https://download.oracle.com/java/21/latest/jdk-21_{{OS_TYPE}}-x64_bin.{{ARCHIVE_TYPE}}'
+    ],
     [
       '20',
       '20',