Mark Windows-only tests

Comment
diff --git a/src/test/java/org/apache/commons/io/FileSystemUtilsTest.java b/src/test/java/org/apache/commons/io/FileSystemUtilsTest.java
index b6af69a..7450564 100644
--- a/src/test/java/org/apache/commons/io/FileSystemUtilsTest.java
+++ b/src/test/java/org/apache/commons/io/FileSystemUtilsTest.java
@@ -31,6 +31,8 @@
 import java.util.Locale;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.MethodSource;
 
@@ -63,6 +65,7 @@
             return new Process() {
                 @Override
                 public void destroy() {
+                    // nnop
                 }
 
                 @Override
@@ -338,12 +341,14 @@
         assertEquals(189416L, fsu.freeSpaceUnix("/", false, false, NEG_1_TIMEOUT));
     }
 
+    @EnabledOnOs(value = OS.WINDOWS)
     @ParameterizedTest
     @MethodSource("getIllegalFileNameChars")
     public void testGetFreeSpaceWindows_IllegalFileName(final char illegalFileNameChar) throws Exception {
         assertThrows(IllegalArgumentException.class, () -> new FileSystemUtils().freeSpaceWindows("\\ \"" + illegalFileNameChar, NEG_1_TIMEOUT));
     }
 
+    @EnabledOnOs(value = OS.WINDOWS)
     @Test
     public void testGetFreeSpaceWindows_IllegalFileNames() throws Exception {
         assertThrows(IllegalArgumentException.class, () -> new FileSystemUtils().freeSpaceWindows("\\ \"", NEG_1_TIMEOUT));