java/util/zip/DataDescriptorSignatureMissing.java uses @ignore w/o bug-id

java/util/zip/DataDescriptorSignatureMissing.java has '@ignore This test has brittle dependencies on an external working python.'; canonically, @ignore should be followed by the id of the bug which describes the problem and will be used to eventually fix it.

the more appropriate solutions for a situation when tests have special requirements:
 - use `@requires` to check that the necessary conditions are met. in this case, this might including the creation of new at-requires property (in /test/lib/jtreg-ext/requires/VMProps.java or better a separate EnvProps class) which check that python is available;
 - using custom check login in tests and throwing jtreg.SkippedException;
 - using '/manual' jtreg option, which will exclude tests from automated runs, yet will still be possible for "manual" execution by direct jtreg invocation