feat: add Julia package ecosystem (JLSEC-*) and linting support

[mbauman]

This is for https://github.com/JuliaLang/SecurityAdvisories.jl

[mbauman]

Note that we should be able to revert 98e42e3 once a new version of Semantic is published that includes Julia support (google/osv-scalibr#1426) is published.

[G-Rath]

the OSV libs use each other with pseudo versions so you don't need to wait for a new release, you can just update to point at the latest commit - that should let you start specifying Julia and then I believe switch to using our versionsExistInGeneric function as I'm not seeing any other reason that shouldn't work?

also can you please add some tests for the linter changes 🙂

[mbauman]

I've added tests and bumped semantic. The versions.json file that we're using there isn't a straight array of versions; it's a key-value with information about the registration and "yank" (read: invalidation) dates, so we can't directly use the generic parser. We do have control over that file's schema and nobody else is using it yet — it's new.

[G-Rath]

so we can't directly use the generic parser.

The generic parser extracts an array of versions using a gjson selector which you can customize - in this case @keys should be what you want; for reference, hackage has a similar structure

https://gjson.dev/

[another-rex]

LGTM, thanks!

[another-rex]

Can you have a look at the DCO check? Thanks