Add support for Node v20 and drop support for Node v16

[pziemkowski]

Description

Node 20 is out for 5 months now so it's about time we add it to our CI to test against.
Node 16 is out of maintenance since last week so it's about time

Describe the solution you'd like

We should migrate services using Node to version 18 (infra-functions, workers, localwsserver).

We should add version 20 to Github Actions and remove 16.

We should upgrade documentation that lowest supported verison of Node is 18.

Describe alternatives you've considered

No response

Additional context

No response

Validations

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• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.