Install pytest-sphinx with conda not pip

Author: maresb

environment.yml

@@ -33,8 +33,7 @@ dependencies:
   - pytest-xdist
   - pytest-benchmark
   - pytest-mock
-  - pip:
-    - pytest-sphinx
+  - pytest-sphinx
   # For building docs
   - sphinx>=5.1.0,<6
   - sphinx_rtd_theme