[Tests] Limit IOUtilTests on Windows (elastic#124716) (elastic#124729)

On Windows read-only directories where files cannot be stored are not
supported. It makes this test irrelevant for this OS.

Author: jozala

test/test-clusters/src/test/java/org/elasticsearch/test/cluster/util/IOUtilsTests.java

@@ -9,6 +9,7 @@
 
 package org.elasticsearch.test.cluster.util;
 
+import org.junit.Assume;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -56,6 +57,8 @@ private void assertFileExists(Path path) throws IOException {
 
     @Test
     public void testSyncWithLinksThrowExceptionWhenDestinationIsNotWritable() throws IOException {
+        Assume.assumeFalse("On Windows read-only directories are not supported", OS.current() == OS.WINDOWS);
+
         // given
         Path sourceDir = Files.createTempDirectory("sourceDir");
         Files.createFile(sourceDir.resolve("file1.txt"));