`babel-runtime` should not be a dependency

[niftylettuce]

This package should be pre-compiled with babel when it is published to npm.

https://github.com/benjycui/omit.js/blob/master/package.json#L41

Also there is a deprecation warning due to omit.js using babel-runtime versus @babel/runtime:

omit.js > babel-runtime > core-js@2.6.11: core-js@<3 is no longer maintained and not recommended for usage due to the number of issues. Please, upgrade your dependencies to the actual version of core-js@3.

[niftylettuce]

Thank you