Remove Narayana support

The Spring Boot integration is now handled by the Narayana project
itself at https://github.com/snowdrop/narayana-spring-boot

This commit removes our support.

Closes gh-12026

spring-boot-samples/pom.xml

@@ -54,7 +54,6 @@
 		<module>spring-boot-sample-jpa</module>
 		<module>spring-boot-sample-jta-atomikos</module>
 		<module>spring-boot-sample-jta-bitronix</module>
-		<module>spring-boot-sample-jta-narayana</module>
 		<module>spring-boot-sample-jta-jndi</module>
 		<module>spring-boot-sample-junit-jupiter</module>
 		<module>spring-boot-sample-kafka</module>