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Use stable Python C API for building Rust extension (#10120)

* Use stable Python C API for building Rust extension

This commit tweaks the rust extension code to start using the PyO3 abi3
flag to build binaries that are compatible with all python versions, not
just a single release. Previously, we were building against the version
specific C API and that resulted in needing abinary file for each
supported python version on each supported platform/architecture. By
using the abi3 feature flag and marking the wheels as being built with
the limited api we can reduce our packaging overhead to just having one
wheel file per supported platform/architecture.

The only real code change needed here was to update the memory
marginalization function. PyO3's abi3 feature is incompatible with
returning a big int object from rust (the C API they use for that
conversion isn't part of the stable C API). So this commit updates the
function to convert to create a python int manually using the PyO3 api
where that was being done before.

Co-authored-by: Jake Lishman <jake.lishman@ibm.com>

* Set minimum version on abi3 flag to Python 3.8

* Fix lint

* Use py_limited_api="auto" on RustExtension

According to the docs for the setuptools-rust RustExtension class:
https://setuptools-rust.readthedocs.io/en/latest/reference.html#setuptools_rust.RustExtension
The best setting to use for the py_limited_api argument is `"auto"` as
this will use the setting in the PyO3 module to determine the correct
value to set. This commit updates the setup.py to follow the
recommendation in the docs.

* Update handling of phase input to expval rust calls

The pauli_expval module in Rust that Statevector and DensityMatrix
leverage when computing defines the input type of the phase argument as
Complex64. Previously, the quantum info code in the Statevector and
DensityMatrix classes were passing in a 1 element ndarray for this
parameter. When using the the version specific Python C API in pyo3 i... (continued)

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