Remove the assertion from RetryState.isLastAttempt

Turned out, `assertFalse(operationTimeout && attemptLimit)` holds only as long as there is `retryUntilTimeoutThrowsException`, which I am going to remove, because it is useless. There is no reason to add an assertion that is known to be removed soon.

Author: stIncMale

driver-core/src/main/com/mongodb/internal/async/function/RetryState.java

@@ -360,7 +360,6 @@ public boolean isFirstAttempt() {
     private boolean isLastAttempt(final Throwable attemptException) {
         boolean operationTimeout = retryUntilTimeoutThrowsException && attemptException instanceof MongoOperationTimeoutException;
         boolean attemptLimit = attempt() == attempts - 1;
-        assertFalse(operationTimeout && attemptLimit);
         return loopState.isLastIteration() || operationTimeout || attemptLimit;
     }