Refactor newTopics filtering with removeIf

Replace manual Iterator loop with Collection.removeIf() to improve code
readability and maintainability.

The original implementation used a while loop with Iterator to remove
entries that don't match the createOrModifyTopic predicate. While this
worked, it required more boilerplate code and was less expressive.

The new implementation uses the removeIf method introduced in Java 8,
which directly expresses the filtering operation in a single line. This
reduces method complexity and makes the code more idiomatic.

Signed-off-by: Choi Wang Gyu <[email protected]>

Author: cwangg897

spring-kafka/src/main/java/org/springframework/kafka/core/KafkaAdmin.java

@@ -347,10 +347,8 @@ protected Collection<NewTopic> newTopics() {
 				}
 			}
 		}
-		Map<String, NewTopic> filteredMap = newTopicsMap.entrySet().stream()
-				.filter(entry -> this.createOrModifyTopic.test(entry.getValue()))
-				.collect(Collectors.toMap(Entry::getKey, Entry::getValue));
-		return new ArrayList<>(filteredMap.values());
+		newTopicsMap.entrySet().removeIf(entry -> !this.createOrModifyTopic.test(entry.getValue()));
+		return new ArrayList<>(newTopicsMap.values());
 	}
 
 	@Override