Perhaps a bit controversial, but at my work we have a test utility package which has Jest as a direct dependency. Because of this we do not include Jest as a (dev) dependency in the package.json files of our apps/libs. As a result I was unable to use the neotest-jest plugin successfully.

I was thinking that actually in order for Jest to run in a project, the only precondition is that the binary is available in node_modules/.bin/, so perhaps it makes more sense to check if that's the case instead of reading the package.json files.

This has fixed my issue, but perhaps there are some ramifications of this approach which I hadn't considered yet. If so feel free to close this PR.

If this does seem like a good general improvement, then some additional commits might be in order to remove the code that checks the package.json files.