Reported issue: awslabs/amazon-dynamodb-local-samples#13

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This project reproduces an exception in DynamoDBLocal when embedded version is used:

com.amazonaws.AmazonServiceException: Regions are not supported in LocalDynamoDB (Service: null; Status Code: 400; Error Code: InvalidAction; Request ID: null; Proxy: null)

	at com.amazonaws.services.dynamodbv2.local.embedded.DDBExceptionMappingInvocationHandler.handleDynamoDBLocalServiceException(DDBExceptionMappingInvocationHandler.java:50)
	at com.amazonaws.services.dynamodbv2.local.embedded.DDBExceptionMappingInvocationHandler.invoke(DDBExceptionMappingInvocationHandler.java:126)
	at jdk.proxy2/jdk.proxy2.$Proxy76.setRegion(Unknown Source)
	at com.amazonaws.services.kinesis.clientlibrary.lib.worker.Worker.setField(Worker.java:1262)
	at com.amazonaws.services.kinesis.clientlibrary.lib.worker.Worker.access$500(Worker.java:92)
	at com.amazonaws.services.kinesis.clientlibrary.lib.worker.Worker$Builder.build(Worker.java:1477)
	at com.amazonaws.services.dynamodbv2.streamsadapter.StreamsWorkerFactory.createDynamoDbStreamsWorker(StreamsWorkerFactory.java:165)

For comparison, when Jetty version (or a client configured for production use) is used, the following code:

// com.amazonaws.services.kinesis.clientlibrary.lib.worker.Worker.setField
    private static <S, T> void setField(final S source, final String field, final Consumer<T> t, T value) {
        try {
            t.accept(value);
        } catch (UnsupportedOperationException e) {
            LOG.debug("Exception thrown while trying to set " + field + ", indicating that "
                    + source.getClass().getSimpleName() + "is immutable.", e);
        }
    }

catches an exception thrown here:

// com.amazonaws.AmazonWebServiceClient.setRegion
    public void setRegion(Region region) throws IllegalArgumentException {
        checkMutability();
        // ...
    }

// com.amazonaws.AmazonWebServiceClient.checkMutability
    protected final void checkMutability() {
        if (isImmutable) {
            throw new UnsupportedOperationException(
                    "Client is immutable when created with the builder.");
        }
    }

... and no hacks have to be done in tests.

Since Spring Boot 3.2 requires Jetty 12 while DynamoDBLocal still uses Jetty 11, we need to use embedded version of the mock, or prepare even bigger hacks for DynamoDBLocal to work with Spring Boot 3.2.