[fix][build][branch-4.0] Fix issue in backporting PR #25644

The backport of #25644 introduced a Java record (`Table<V>`) in
`ConcurrentLongHashMap`, which fails to compile on branch-4.0 because the
`pulsar-common` module targets Java 8 source compatibility. Records require
`-source 16` or higher.

Replace the record with an equivalent static nested final class that exposes
the same `keys()`, `values()`, and `capacity()` accessors, so all existing
call sites continue to work unchanged.

Author: lhotari

pulsar-common/src/main/java/org/apache/pulsar/common/util/collections/ConcurrentLongHashMap.java

@@ -293,7 +293,29 @@ public interface EntryProcessor<V> {
     // previous design had to paper over with Math.min(keys.length, values.length).
     @SuppressWarnings("serial")
     private static final class Section<V> extends StampedLock {
-        private record Table<V>(long[] keys, V[] values, int capacity) { }
+        private static final class Table<V> {
+            private final long[] keys;
+            private final V[] values;
+            private final int capacity;
+
+            Table(long[] keys, V[] values, int capacity) {
+                this.keys = keys;
+                this.values = values;
+                this.capacity = capacity;
+            }
+
+            long[] keys() {
+                return keys;
+            }
+
+            V[] values() {
+                return values;
+            }
+
+            int capacity() {
+                return capacity;
+            }
+        }
 
         // Section is Serializable only by inheritance from StampedLock; never actually serialized.
         @SuppressFBWarnings("SE_BAD_FIELD")