SpringBoot Upgrade to Maven Shade Plugin 3.2.4

This PR updates maven-shade-plugin to 3.2.4.

The resource transformer was updated here https://github.com/spring-projects/spring-boot/commit/5e7917e33a142ea41e7e787478182122466d13f1, but the plugin version in spring-boot-dependencies was not updated.

Comment From: wilkinsona

Thanks very much for making your first contribution to Spring Boot, @anshlykov, and for taking care of removing the no-longer-needed prohibited version.