feat: add support for Julia projects

[cadojo]

Julia projects have their versions specified in their dependency files, not their lock files. Their dependency files can be named JuliaProject.toml or (more commonly) Project.toml. Each package version is held by the 'version' key in the project TOML file. This makes release-please parsing simple!

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• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #2152

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[chingor13]

Thanks for this! It seems reasonable, but the tests are failing.

[cadojo]

Thanks for this! It seems reasonable, but the tests are failing.

@chingor13 I've updated the listing rules! Would it be possible for you to enable CI for this PR?

[cadojo]

This is ready for review! Tests should be passing, and I've opened a draft PR in a Julia monorepo I maintain as an example.

[cadojo]

@chingor13 could you please enable CI once again? I've done some more testing locally, and I'm confident tests will pass (for non-Windows tests at least, where I'm able to test locally).

[cadojo]

I'm unsure about this change, but I needed it to run tests locally.

[cadojo]

@chingor13 could you please enable CI? I think tests should pass now.