Update default runtime to node 20

[benwells]

Description: Node 16 has reached end of life on September 11, 2023.

https://github.com/actions/runner now supports node 20 as of v2.308.0 and we encourage teams to update their actions to run on node 20 runtime by default.

Changelog here

Reference to similar previous PR when we migrated to node16

Justification: Justification or a use case for your proposal.

Are you willing to submit a PR?

[marko-zivic-93]

Hello @benwells,

Thank you for the heads up, we will start tackling this issue as soon as possible :)

[erikburt]

Relevant blog post: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/

[SvenStaehs]

I believe this can be closed with the recent #1110 and release v9.0.0 right?