Research older Node versions support

[BioPhoton]

This needs some research (timebox: 0.5 day):

• Let's figure which minimum Node version we should support.
• Let's check which newer Node APIs we're using (e.g. structuredClone) and what we can do to replace them (e.g. polyfill).
• Let's add Node version to GitHub Actions matrix and see how good other actions support is.