Upgrade Solhint version to catch new rules

[AlissonRS]

I'm using Solhint 3.6.2, which provides a rule immutable-vars-naming to use SNAKE_CASE for immutable state, there was also a PR on Solhint repo to fix the var-name-mixedcase rule to disregard immutable variables, which was added in Solhint 3.5.1.

This extension is using Solhint 3.4.0 though, so it's making VS Code to give false positive errors:

Is there a way to configure the extension to use a higher Solhint version, or rather would it be ok to upgrade Solhint version on this extension? I'm keen on opening a PR for this if this is desirable.

Thanks for such a great extension!!!

[juanfranblanco]

@AlissonRS it is now integrated in the latest versions