fix: avoid global unlimited config

[Eomm]

fixes #88

I choose to use a number instead of adding a new long-lived object in memory to track the state of the event.
This reduces the memory footprint a bit.

[Uzlopak]

How is the performance?

[Eomm]

best of 3 runs. This branch win

This branch

warn x 79,974,928 ops/sec ±0.44% (100 runs sampled)
(node:45152) [FST_ERROR_CODE_1] FastifyWarning: message
(Use `node --trace-warnings ...` to show where the warning was created)
(node:45152) [FST_ERROR_CODE_3] FastifyWarning: message

main:

warn x 62,636,303 ops/sec ±0.28% (100 runs sampled)
(node:44977) [FST_ERROR_CODE_1] FastifyWarning: message
(Use `node --trace-warnings ...` to show where the warning was created)
(node:44977) [FST_ERROR_CODE_3] FastifyWarning: message

[Uzlopak]

LGTM