Support coverage plugins with sys.monitoring

[scoder]

Is your feature request related to a problem? Please describe.

Running coverage.py on Cython code with sys.monitoring in Py3.13 disables the Cython coverage plugin: https://github.com/nedbat/coveragepy/blob/7f336228d78d8338239d4da4d4de3ade0abd0901/coverage/control.py#L565-L568

Describe the solution you'd like Plugins should work the same with the old tracing and new monitoring infrastructure.

Additional context I'm currently working on getting Cython to use the monitoring C-API, but found that coverage.py doesn't support both together as it stands.