fix: NPE for /actuator/configprops

```
java.lang.NullPointerException
	at java.base/java.util.stream.Collectors.lambda$uniqKeysMapAccumulator$1(Collectors.java:177)
	at java.base/java.util.stream.ReduceOps$3ReducingSink.accept(ReduceOps.java:169)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578)
	at org.springframework.boot.actuate.context.properties.ConfigurationPropertiesReportEndpoint.describeBeans(ConfigurationPropertiesReportEndpoint.java:190)
	at org.springframework.boot.actuate.context.properties.ConfigurationPropertiesReportEndpoint.extract(ConfigurationPropertiesReportEndpoint.java:138)
	at org.springframework.boot.actuate.context.properties.ConfigurationPropertiesReportEndpoint.configurationProperties(ConfigurationPropertiesReportEndpoint.java:124
```

Author: qxo

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpoint.java

@@ -131,7 +131,7 @@ public void keysToSanitize(String... keysToSanitize) {
 
 	@ReadOperation
 	public ApplicationConfigurationProperties configurationProperties() {
-		return extract(this.context, (bean) -> true);
+		return extract(this.context, (bean) -> bean != null);
 	}
 
 	@ReadOperation