Fix Javadoc warnings due to Java 21 update (+ some other warnings)

The default implicit constructor must also have a doc comment, so I have to make it explicit and either properly restrict the visibility of the constructor, or actually document it.

pandalib-cli/src/main/java/fr/pandacube/lib/cli/log/CLILogger.java

@@ -97,5 +97,7 @@ public class CLILogger {
 		t.start();
 		return ps;
 	}
+
+	private CLILogger() {}
 	
 }