Update coverage call, don't install in editable mode in testing

[rly]

Motivation

Follow-up to https://github.com/NeurodataWithoutBorders/nwbinspector/pull/450#discussion_r1583475196

https://setuptools.pypa.io/en/latest/userguide/development_mode.html says

Editable installs are not a perfect replacement for regular installs in a test environment. When in doubt, please test your projects as installed via a regular wheel. There are tools in the Python ecosystem, like tox or nox, that can help you with that (when used with appropriate configuration).

We use editable installs in testing in a couple places, mostly to help coverage find the sources, but we can configure that in pyproject.toml instead.

How to test the behavior?

Run all GitHub actions

Checklist

• [x] Did you update CHANGELOG.md with your changes?
• [x] Does the PR clearly describe the problem and the solution?
• [x] Have you reviewed our Contributing Guide?
• [x] Does the PR use "Fix #XXX" notation to tell GitHub to close the relevant issue numbered XXX when the PR is merged?

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.70%. Comparing base (3146c97) to head (9be854b).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #1107 +/- ## ======================================= Coverage 88.70% 88.70% ======================================= Files 45 45 Lines 9745 9745 Branches 2767 2767 ======================================= Hits 8644 8644 Misses 779 779 Partials 322 322 ```

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