Replace pybind11 with nanobind in Catalyst's core

[joeycarter]

Context: The Catalyst core contains two Python extension modules (importable Python modules written in C/C++):

• mlir/python/PyCompilerDriver.cpp
• mlir/python/QuantumExtension.cpp

The Python-C++ bindings were originally implemented using pybind11. This PR is part of a larger effort to replace all pybind11 code with nanobind.

Description of the Change:

This change replaces all the pybind11 code in mlir/python/PyCompilerDriver.cpp with the equivalent nanobind objects and operations.

This change also removes the MLIR python module QuantumExtension entirely, along with associated tests and infrastructure, since (a) it depends on upstream MLIR Python bindings written in pybind11: mlir/Bindings/Python/PybindAdaptors.h, which would be quite onerous to port to nanobind, and (b) we do not actually use these dialect extensions, nor do we ship them with our wheels.

Benefits:

See Epic 68472 for a list of nanobind's benefits.

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[sc-72842]

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