ran copier update, which changed testing action

[sschmidt23]

Problem & Solution Description (including issue #)

Simply ran copier update which added the new line to the testing and coverage GitHub action, we'll see if the codecov report actually uploads properly now.

Code Quality

• My code follows the code style of this project
• I have written unit tests or justified all instances of #pragma: no cover; in the case of a bugfix, a new test that breaks as a result of the bug has been added
• My code contains relevant comments and necessary documentation for future maintainers; the change is reflected in applicable demos/tutorials (with output cleared!) and added/updated docstrings use the NumPy docstring format
• Any breaking changes, described above, are accompanied by backwards compatibility and deprecation warnings

[sschmidt23]

I logged in to codecov and copied the token as as a repo secret, looks like that does work and the codecov upload was successful (there are no changes to evaluate so the codecov report is boring for this one, but it did work).