Adding labels to split StopWatch feature - checkstyle

Author: edelgadoh

src/test/java/org/apache/commons/lang3/time/StopWatchTest.java

@@ -632,8 +632,8 @@ void testNanoSplitsWithLabel() {
 
     // Note: On macOS the clock granularity and scheduling can cause minor deviations.
     static void assumeNotMacOs13() {
-        String os = System.getProperty("os.name").toLowerCase();
-        String version = System.getProperty("os.version");
+        final String os = System.getProperty("os.name").toLowerCase();
+        final String version = System.getProperty("os.version");
         Assumptions.assumeTrue(!(os.contains("mac") && version.startsWith("13")),
                 () -> "Skipping test on macOS 13");
     }