startStatement() should not be required in Neo4jItemReader

Bug description
In Neo4jItemReaderBuilder, startStatement(String startStatement) is required, but Neo4j itself deprecated the START statement and throw error when used. If not used, application will throw BeanCreationException with message java.lang.IllegalArgumentException: startStatement is required.

Environment
Spring Boot: 2.7.0
Kotlin: 1.6.10
Neo4j: 4.4.4

Steps to reproduce

@Bean
    fun postReader(): ItemReader<Post> {
        return Neo4jItemReaderBuilder<Post>()
            .name("postReader")
            .sessionFactory(getSessionFactory())
            .startStatement("")
            .matchStatement("(p:Post)")
            .returnStatement("p")
            .targetType(Post::class.java)
            .pageSize(1000)
            .build()
    }

Expected behavior
startStatement() should be optional, not mandatory.

Start by locating Neo4jItemReaderBuilder and read the validation around startStatement(String startStatement), then inspect any related builder tests. Reproduce the BeanCreationException with the shown configuration and verify that omitting startStatement allows the reader to build while matchStatement and returnStatement still work.