[FEA] Add build/run environment output as a separate step in build/test workflows

Often when CI fails during package upgrades it is because the dependencies are not yet up to date in the installed environment. Spotting this is sometimes complicated because either the test run script doesn't run the relevant command (conda list or pip freeze), or it's lost in installation/test run backtraces.

It would be nice if there were a step in the actions workflow that just ran conda list or pip freeze as a appropriate that we could expand as a step in the CI run.

I think it would have to run after the repository-provided test script (or else the workflows would have to split the "create environment" from the "run tests" phase).

We could do this ad-hoc in each repository's run script, but that doesn't give nice clicky sections in the CI run, and is easy to miss because it's not always in a consistent place.

Start by reading the reusable build/test workflows and the repository-provided test script entry points. Compare the conda and pip environment cases, then verify that the package listing runs after the test script in its own expandable CI step. Done means the relevant workflow runs conda list or pip freeze with the output visible separately.