Enabled TieredPGO and ServerGarbageCollection

[Aaronontheweb]

Goal is reduce latency and make Lighthouse more reliable, at the cost of slightly more CPU consumption.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ Aaronontheweb
❌ kodiakhq[bot]
_{You have signed the CLA already but the status is still pending? Let us recheck it.}