Update from node12 to node16

[artfisica]

Hi,

Thanks for such a useful Action!

Can you consider updating the version of Node as per GitHub:

• https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/
• https://docs.github.com/en/actions/creating-actions/metadata-syntax-for-github-actions#runs-for-javascript-actions

I have tested successfully in private repos that were using webfactory/ssh-agent@v0.5.4 version.
Thanks!

[sebastiankugler]

@artfisica thank you very much for contributing! Since there is already an identical PR (#132), I'm closing this one.

[artfisica]

Thanks! @sebastiankugler ! and excuses for not checking the existing PRs before :O (so identical I even used the v0.6.0 for my tests, cool).