fix: remove deprecated method & version spec

[heywhy]

• remove deprecated method
• update version constraints to allow ease of upgrades in dependent projects. e.g. recase couldn't be updated in a project of mine due to this tight constraint.
• general code cleanups due to compiler warnings in elixir 1.19

[heywhy]

@qgadrian thank you for this project. i hope this pr can be looked into as soon as possible.

[qgadrian]

thank you for this PR @heywhy

I will hold off the merge, it's a breaking change and will required a major version update 🙏