refactor(flowable): remove unnecessary inheritance from FlowableBufferTimedFlushable

The class no longer requires inheritance from FlowableBufferTimedFlushable as its functionality is redundant. Simplified the class hierarchy for better maintainability.

Author: OrezzerO

client/src/main/java/com/influxdb/client/internal/flowable/FlowableBufferTimedFlushable.java

@@ -35,8 +35,7 @@
  * @param <U> the output value type
  * @see FlowableBufferTimed
  */
-public final class FlowableBufferTimedFlushable<T, U extends List<? super T>> extends Flowable<U>
-        implements FlowableTransformer<T, U> {
+public final class FlowableBufferTimedFlushable<T, U extends List<? super T>> extends Flowable<U> {
 
     final Publisher<T> source;
     final Publisher<Boolean> flusher;
@@ -67,11 +66,6 @@ public FlowableBufferTimedFlushable(Publisher<T> source,
         this.restartTimerOnMaxSize = true;
     }
 
-    @Override
-    public @NonNull Publisher<U> apply(@NonNull final Flowable<T> upstream) {
-        return new FlowableBufferTimedFlushable<>(upstream, flusher, timeskip, unit, maxSize, scheduler, bufferSupplier);
-    }
-
     @Override
     protected void subscribeActual(@NonNull final Subscriber<? super U> subscriber) {
         Scheduler.Worker w = scheduler.createWorker();