Updating for v5

[nrayburn-tech]

Prerequisites

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Issue

I'm looking to update this repo for v5. fastify/fastify#5116

From what I can tell this just requires updating the tsconfig target to ES2023 (Based on what's available in Node 18 from https://node.green). Even when using ES2023, the caveat from https://github.com/fastify/tsconfig#configuration-target still applies. There is not any version of node that currently supports regex match indices.

Should there be a next branch made or should I just target main?