Spring Boot CLI manifest does not have Implementation-Version header anymore

[snicoll]

This is a regression. Here's the MANIFEST.mf for 2.3.5.RELEASE:

Manifest-Version: 1.0
Implementation-Title: Spring Boot CLI
Automatic-Module-Name: spring.boot.cli
Implementation-Version: 2.3.5.RELEASE
Built-By: Spring
Build-Jdk-Spec: 1.8

The one for 2.3.6.RELEASE (staged, not released) is as follows:

Manifest-Version: 1.0
Start-Class: org.springframework.boot.cli.SpringCli
Class-Loader: groovy.lang.GroovyClassLoader
Main-Class: org.springframework.boot.loader.JarLauncher

[snicoll]

Moving to task as we haven't released anything with that regression yet hopefully.