Java syntax not yet supported by `javaparser` fails during dependency inference

[stuhood]

https://github.com/javaparser/javaparser/blob/master/FEATURES.md describes the Java language features supported by the javaparser library: notably missing as of 3.24.4 is support for sealed class, which seems to be relatively widely used (in both spring-boot and junit5).

This issue is an umbrella for other syntax issues that folks might encounter. Contributing support for these syntaxes upstream would help unblock using them in code built by Pants.