incompatible with Node 20

[turadg]

Describe the bug

Several packages depend on Bufferfile, which is incompatible with Node 20

• drop Node 16 (EOL) #8365 (comment)
• fix Node 20 compatibility agoric-labs/BufferFromFile#2

Platform Environment

• Node 20 in GH CI

Additional context

When fixing this, update code points for all mentions of this issue. Also update the package.json engines to include 20. Might be as simple as reverting: build: defer Node 20 compatibility

[dckc]

We can’t use Node 20 and anyone using the Active LTS can’t use Agoric SDK.

• 11 Dec: @Chris-Hibbert reported complaints from yarn about node versions; @ivanlei noted this issue.
• 18 Dec: @LuqiPan ran into this when trying to follow agoric-sdk/README.md

The cost to address this is mostly solving the circular buffer in flight-recorder.js which uses BufferFromFile which doesn’t work in Node 20 and seems to be no longer maintained

[turadg]

fixed in #8920