Quartz.Serialization.Json

This package is empty. The Json.NET job store serializer is Quartz.Serialization.Newtonsoft from 4.0 on — the name says which JSON library it uses, now that the System.Text.Json one is built into Quartz and is the default. Reference Quartz.Serialization.Newtonsoft instead of this, call UseNewtonsoftJsonSerializer() as before, and read the migration guide for the rest of the upgrade.

It is published at every 4.x version for one reason: a dependency bot that updates Quartz and this package as one group resolves that group to the newest version every member has. With nothing under this id above 3.20.1 the group stops there, and the 4.0 pull request the bot had already opened is closed as superseded. Quartz.OpenTracing and Quartz.OpenTelemetry.Instrumentation deliberately have no such package: neither has a 4.x replacement, and an empty one would hide that rather than say it.