Add priorities for editables

[charliermarsh]

Summary

We weren't setting a priority for editables, so they were being visited last.

I think there's still a problem whereby we're not aggressive enough in visiting recursive extras (and, in fact, that's making it really hard to write a test -- I wrote a test, but the most-reduced case still fails, and I'd need to add a layer of indirection to make it fail-on-main-but-pass-on-this-branch), but that problem likely already existed on main prior to #3087, so I just want to get this quick fix out now.

Closes #3127.

Test Plan

• git clone https://github.com/cda-tum/mqt-core.git
• cargo run venv
• cargo run pip install 'scikit-build-core[pyproject]>=0.8.1' 'setuptools_scm>=7' 'pybind11>=2.12' --resolution=lowest-direct
• cargo run pip install --no-build-isolation '-ve.[test,qiskit,evaluation,coverage]' --resolution=lowest-direct

[charliermarsh]

I plan to follow-up with another fix and a real test.