cleanup downstream

- remove weldx
- change abacusutils tests per suggestion

.github/workflows/downstream.yml

@@ -70,7 +70,6 @@ jobs:
       # Any env name which does not start with `pyXY` will use this Python version.
       default_python: '3.12'
       envs: |
-        - linux: weldx
         - linux: sunpy
         - linux: dkist
         - linux: abacusutils

tox.ini

@@ -334,9 +334,7 @@ extras =
 commands_pre =
     bash -c "pip freeze -q | grep 'asdf @' > {env_tmp_dir}/requirements.txt"
     git clone https://github.com/abacusorg/abacusutils.git
-    pip install -vU setuptools wheel scipy Cython 'numpy<2'  # for classy and corrfunc
-    pip install --no-build-isolation classy corrfunc
-    pip install -e abacusutils[test]
+    pip install -e ./abacusutils pytest
     pip install -r {env_tmp_dir}/requirements.txt
 # make an empty pytest.ini to prevent pytest from crawling up
 # one directory and finding the pytest configuration for the asdf