Fix Build on OSX

OSX shows up as `mac` for the platform as well.

Author: original-brownbear

buildSrc/src/main/java/org/elasticsearch/gradle/Jdk.java

@@ -37,7 +37,7 @@ public class Jdk implements Buildable, Iterable<File> {
     private static final List<String> ALLOWED_VENDORS = List.of("adoptopenjdk", "openjdk");
     static final Pattern VERSION_PATTERN =
         Pattern.compile("(\\d+)(\\.\\d+\\.\\d+)?\\+(\\d+(?:\\.\\d+)?)(@([a-f0-9]{32}))?");
-    private static final List<String> ALLOWED_PLATFORMS = Collections.unmodifiableList(Arrays.asList("darwin", "linux", "windows"));
+    private static final List<String> ALLOWED_PLATFORMS = Collections.unmodifiableList(Arrays.asList("darwin", "linux", "windows", "mac"));
 
     private final String name;
     private final Configuration configuration;