feat: add Sentry.Quartz3 for cron monitoring of Quartz.NET 3.x jobs

[wedamija]

Description

Stacked on #5505 (base branch danf/quartz-5505-rebased is a copy of #5505's branch).

Adds Sentry.Quartz3, the Quartz.NET 3.x add-on to Sentry.Quartz (#5505). It compiles the same core files (schedule conversion, slugs, options, check-ins) against Quartz [3.6.0,4.0.0) for net8.0, net9.0, net10.0 and net462, and runs them from an IJobListener, since Quartz 3 has no job middleware.

services.AddQuartz(q => q.AddJobListener<SentryJobListener>());
// or: scheduler.ListenerManager.AddJobListener(new SentryJobListener());

Check-ins and monitor configs work as in Sentry.Quartz: only jobs with [SentryCronMonitorSlug] are monitored, and their trigger's schedule is sent unless SendMonitorConfig is off. A listener can't wrap the job, so there is no per-job scope or exception capture.

Quartz 4 changed IJobListener to return ValueTask with default implementations, so this listener would load there but never be called. It logs an error pointing to Sentry.Quartz instead.

A release-registry entry is needed before the first release.

Motivation

Quartz 4 only targets net10.0, so apps on .NET Framework or older .NET stay on Quartz 3. They need the same check-ins, and sharing the core keeps the extra code to the listener.

Testing

The core tests from Sentry.Quartz.Tests run against Quartz 3.6 on net8.0, net9.0 and net10.0 (and net48 on Windows), plus listener tests and a real-scheduler test. API approval files added.

Docs: getsentry/sentry-docs#19790

[codecov]

Codecov Report

❌ Patch coverage is 71.42857% with 8 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (danf/quartz-5505-rebased@fe97276). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
src/Sentry.Quartz3/SentryJobListener.cs	65.21%	7 Missing and 1 partial ⚠️

Additional details and impacted files

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##             danf/quartz-5505-rebased    #5668   +/-   ##
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