Support for `sys.monitoring` backend?

**Is your feature request related to a problem? Please describe.**
Python 3.12 added a new namespace [sys.monitoring](https://docs.python.org/3/library/sys.monitoring.html) ([PEP669](https://peps.python.org/pep-0669/)) that allows tracing Python code with lower overhead than previous methods. Numbers I have seen range between a 10x to 100x speed up of code running in between break points. It would be great if pudb could make use of this.

**Describe the solution you'd like**
Recently, in Python 3.14 (still in alpha), the Bdb class was [updated](https://github.com/python/cpython/pull/124533) to support a `backend='monitoring'` option. Pudb mostly relies on `Bdb` (I think), so perhaps it could add a preference for making use of this new backend starting with Python 3.14.

**Describe alternatives you've considered**
None

**Additional context**
I haven't looked closely at Pudb's interface to Bdb. A quick search shows one call to `sys.settrace`. That might work around the Bdb interface which supports `sys.settrace` and `sys.monitoring` backends and need to be modified for the `sys.monitoring` case. Also, there could be other things in the Pudb code that make it impractical to use the monitoring backend. I haven't looked into this thoroughly enough so far. For now, I wanted to raise awareness about the potential performance improvement.

Start by tracing pudb's Bdb integration and the reported sys.settrace call; compare them with Python 3.14's Bdb backend='monitoring' support and the sys.monitoring API described in PEP 669. Determine the scope of adding a monitoring preference and whether existing debugger behavior remains supported across Python versions.

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