Fix docs build: suppress upstream type-hint warnings, restore -W

Suppress sphinx-autodoc-typehints warnings from upstream libraries:
- ColorType forward reference from matplotlib.figure.Figure
- Guarded iris import from xarray.core.dataarray
- Guarded folium import from geopandas.geodataframe

These are optional deps of upstream packages, not our issue.
Restores -W (warnings as errors) to match the scverse template.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: timtreis

docs/conf.py

@@ -142,6 +142,13 @@
 pygments_style = "default"
 katex_prerender = shutil.which(katex.NODEJS_BINARY) is not None
 
+suppress_warnings = [
+    # matplotlib.figure.Figure references ColorType which isn't importable in the docs env
+    "sphinx_autodoc_typehints.forward_reference",
+    # xarray (iris) and geopandas (folium) have guarded TYPE_CHECKING imports for optional deps
+    "sphinx_autodoc_typehints.guarded_import",
+]
+
 # Ignore warnings.
 nitpicky = False  # TODO: solve upstream.
 

pyproject.toml

@@ -82,7 +82,7 @@ dependency-groups = [ "dev" ]
 dependency-groups = [ "doc" ]
 
 [tool.hatch.envs.docs.scripts]
-build = "sphinx-build -M html docs docs/_build {args}"
+build = "sphinx-build -M html docs docs/_build -W {args}"
 open = "python -m webbrowser -t docs/_build/html/index.html"
 clean = "git clean -fdX -- {args:docs}"