Support unnamed lambda parameters

[Vithor112]

Java officially supports unnamed variables as of version 22 (see JEP 456). Spotless issues a warning when using it in a lambda context.

                                    (_, idToStrategy) -> {
                                        idToStrategy.put(username, strategy);
                                        return idToStrategy;
                                    });

Using GJF last release 1.34.1 results in

[WARNING] Issue parsing some source. 1 problems. First problem: (line 48,col 38) '_' is a reserved keyword.
[WARNING] Not able to parse path='OMMITED' with com.github.javaparser.JavaParser@45ae53aa

[tbroyer]

com.github.javaparser.JavaParser is not GJF.