Only pin sphinx-automodapi in RTD environment and add explanatory comment. Try removing new test images.

.readthedocs_env.yml

@@ -22,4 +22,8 @@ dependencies:
   - reproject
   - setuptools
   - sphinx
+  # This pin is to work around a conda verification error
+  # that first appeared in the CI for https://github.com/WorldWideTelescope/pywwt/pull/375.
+  # At the time of writing this, the issue only occurs with sphinx-automodapi==0.17,
+  # which is the newest version.
   - sphinx-automodapi=0.16

setup.py

@@ -135,7 +135,7 @@ setup_args = dict(
             "astropy-sphinx-theme",
             "ipykernel",
             "sphinx>=1.6",
-            "sphinx-automodapi<=0.16",
+            "sphinx-automodapi",
             "numpydoc",
             "jupyter_sphinx",
         ],