Migrate to Pekko

[ex0ns]

I would be in favor to drop akka and use pekko instead, already did the migration on other project and it wend fine.

Should we keep both version in parallel ? I do not use the akka feature of this lib anymore and keeping it as simple as possible would be better IMO.

If anyone is against dropping akka, comment here

[Dessix]

With the choice being between Webhooks with another framework, and a BSL dependency on this one, it leaves this a very desirable improvement.