Add eval frame FFI bindings

[adamgerhant-ai]

Adds FFI bindings for _PyInterpreterState_GetEvalFrameFunc, _PyInterpreterState_SetEvalFrameFunc, and _PyFrameEvalFunction.

In 3.11 _PyInterpreterState_GetEvalFrameFunc returns _PyEval_EvalFrameDefault if it is NULL, so the Option is removed from the return type.

Would it be acceptable to expose _PyEval_EvalFrameDefault in this PR since it may be required by older versions?

[mejrs]

These were removed in #5711

[adamgerhant-ai]

I am using these functions for a custom Python interpreter function hook. This is a useful API to expose to inject code in older versions which do not have sys.monitoring.

A simple search on Github of " = _PyInterpreterState_GetEvalFrameFunc" shows hundreds of usages, so I think it is reasonable for PyO3 to expose this.

[codspeed-hq]

Merging this PR will degrade performance by 25.79%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 139 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	into_u128_max	1.5 µs	2 µs	-25.79%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing adamgerhant-ai:eval-frame-ffi (4b14495) with main (8fcf8fc)}

[davidhewitt]

There is possibly an argument I went too far in removing these. They are somewhat regarded as public and maybe not to be moved.

See e.g. https://mail.python.org/archives/list/python-dev@python.org/message/GFOMU7LP63JUVFMWNJNZJLUMZDRPTUYJ/ and capi-workgroup/decisions#89