Make kernel version detection code in EpollReuseAddrTest more robust (#10556)

Motivation:

When we try to parse the kernel version we need to be careful what to
expect. Especially when a custom kernel is used we may get extra chars
in the version numbers. For example I had this one fail because of my
custom kernel that I built for io_uring:

5.8.7ioring-fixes+

Modifications:

- Try to be a bit more lenient when parsing
- If we cant parse the kernel version just use 0.0.0

Result:

Tests are more robust

transport-native-epoll/src/test/java/io/netty/channel/epoll/EpollReuseAddrTest.java

@@ -28,6 +28,9 @@ import io.netty.handler.logging.LoggingHandler;
 import io.netty.util.NetUtil;
 import io.netty.util.ReferenceCountUtil;
 import io.netty.util.ResourceLeakDetector;
+import io.netty.util.internal.logging.InternalLogLevel;
+import io.netty.util.internal.logging.InternalLogger;
+import io.netty.util.internal.logging.InternalLoggerFactory;
 import org.junit.Assert;
 import org.junit.Assume;
 import org.junit.Ignore;
@@ -44,6 +47,8 @@ import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public class EpollReuseAddrTest {
+    private static final InternalLogger LOGGER = InternalLoggerFactory.getInstance(EpollReuseAddrTest.class);
+
     private static final int MAJOR;
     private static final int MINOR;
     private static final int BUGFIX;
@@ -58,12 +63,24 @@ public class EpollReuseAddrTest {
             MAJOR = Integer.parseInt(versionParts[0]);
             MINOR = Integer.parseInt(versionParts[1]);
             if (versionParts.length == 3) {
-                BUGFIX = Integer.parseInt(versionParts[2]);
+                int bugFix;
+                try {
+                    bugFix = Integer.parseInt(versionParts[2]);
+                } catch (NumberFormatException ignore) {
+                    // the last part of the version may include all kind of different things. Especially when
+                    // someone compiles his / her own kernel.
+                    // Just ignore a parse error here and use 0.
+                    bugFix = 0;
+                }
+                BUGFIX = bugFix;
             } else {
                 BUGFIX = 0;
             }
         } else {
-            throw new IllegalStateException("Can not parse kernel version " + kernelVersion);
+            LOGGER.log(InternalLogLevel.INFO, "Unable to parse kernel version: " + kernelVersion);
+            MAJOR = 0;
+            MINOR = 0;
+            BUGFIX = 0;
         }
     }