TST: Adjustments for my pcdswidgets PR

[ZLLentz]

This makes my pcdswidgets tests pass and helps the docs build properly

See pcdshub/pcdswidgets#96

Change 1: run conda test from installed version

• I've added a build step to pcdswidgets
• This builds and installs correctly
• Without this change, the conda tests run on the pre-built version of the package

Things to consider:

• This makes the test output pretty awful (micromamba/conda-bld/pcdswidgets_1773337587302/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_pla/lib/python3.12/site-packages/pcdswidgets/tests/test_builder.py::test_it_was_built[ui_source0] PASSED [ 1%])
• This ensures that we're testing on the version of the package that gets installed
• I didn't change the pypi tests because the pypi build runs and builds install-time files in the cloned repo, so the tests work for me, but maybe this should also be done on the pypi tests.

Change 2: expose the docs extras argument

• In pcdswidgets I need to keep pyqt out of the pypi requirements for smooth local environment generation
• I then need to add it back for the pip tests and docs builds
• There is a hook for the docs builds that we hadn't been exposing, this exposes it

[tangkong]

This looks reasonable to me

[ZLLentz]

Is it worth keeping the build changes in if I end up removing the extra build step in pcdswidgets? I guess that's not a sure thing yet

[tangkong]

I suppose I don't expect this to really change our current CI processes and opens up more options for us, so it's still a net positive? We can decide when pcdswidgets is in a more stable place I suppose

[ZLLentz]

I'm mainly 50/50 because of the ergonomics of

bld/pcdswidgets_1773337587302/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_pla/lib/python3.12/site-packages/pcdswidgets/tests/test_builder.py::test_it_was_built[ui_source0] PASSED [  1%]

[ZLLentz]

I'm going to merge this in and then if later I decide I don't like placehold_placehold_placehold we'll address that some other way- there must be a way to make conda use like 2 placeholds instead of 50

[ZLLentz]

Geez apparently the long placeholder path is intentional to do some binary string replacement shenanigans, wild stuff

[ZLLentz]

The correct fix for placeholder spam is to actually install the built package instead of running from the env created for the build- but maybe this will never be needed