Disable watchdog if watchdog_timeout_sec config is 0

[ferranbt]

📝 Summary

This PR disables the watchdog if the value from config is zero.

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✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)

[github-actions]

Benchmark results for b2b8d3b

Report: https://flashbots-rbuilder-ci-stats.s3.us-east-2.amazonaws.com/benchmark/b2b8d3b-af6f94a/report/index.html

Date (UTC)	2024-12-03T14:50:30+00:00
Commit	b2b8d3b57d404a0e5df8462be3a33d21fced0913
Base SHA	af6f94ab6f97bea9ce19377c1df255d3b9b73004

Significant changes

Benchmark	Mean	Status
MEV-Boost SubmitBlock serialization/JSON encoding	-4.54%	Performance has improved.

[ZanCorDX]

I don't like hacky constants like 0. I would prefeer to make watchdog_timeout_sec Option in the cfg. The only caveat would be that it would not be fully bacwards compatible since before not having watchdog_timeout_sec would default to 3 min but we don' really use that.

[ZanCorDX]

null object pattern would be nice although for this case, it may be too much (I'll have to copy/paste your changes into multioperator for the other use of the watchdog).