Try and bump doc build napari pin

Author: dstansby

setup.cfg

@@ -47,7 +47,7 @@ napari.manifest =
 
 [options.extras_require]
 docs =
-    napari[all]==0.4.17
+    napari[all]==0.4.18
     numpydoc
     pydantic<2
     pydata-sphinx-theme