[skip-ci] Speed up docs build by limiting toctrees (#9395)

* [skip-ci] Try speeding up docs build

Following https://pydata-sphinx-theme.readthedocs.io/en/stable/user_guide/performance.html

* bump to 3.12

* [skip-ci] latest mamba

* Use mamba

* revert navigation_depth  change

.readthedocs.yaml

@@ -1,9 +1,9 @@
 version: 2
 
 build:
-  os: ubuntu-22.04
+  os: ubuntu-lts-latest
   tools:
-    python: mambaforge-4.10
+    python: mambaforge-latest
   jobs:
     post_checkout:
       - (git --no-pager log --pretty="tformat:%s" -1 | grep -vqF "[skip-rtd]") || exit 183

ci/requirements/doc.yml

@@ -4,7 +4,7 @@ channels:
   - conda-forge
   - nodefaults
 dependencies:
-  - python=3.10
+  - python=3.12
   - bottleneck
   - cartopy
   - cfgrib
@@ -40,6 +40,7 @@ dependencies:
   - sphinx-design
   - sphinx-inline-tabs
   - sphinx>=5.0
+  - sphinx-remove-toctrees
   - sphinxext-opengraph
   - sphinxext-rediraffe
   - zarr>=2.10

doc/conf.py

@@ -88,6 +88,7 @@
     "sphinxext.rediraffe",
     "sphinx_design",
     "sphinx_inline_tabs",
+    "sphinx_remove_toctrees",
 ]
 
 
@@ -198,6 +199,8 @@
 # The master toctree document.
 master_doc = "index"
 
+remove_from_toctrees = ["generated/*"]
+
 # General information about the project.
 project = "xarray"
 copyright = f"2014-{datetime.datetime.now().year}, xarray Developers"
@@ -244,6 +247,7 @@
     repository_url="https://github.com/pydata/xarray",
     repository_branch="main",
     navigation_with_keys=False,  # pydata/pydata-sphinx-theme#1492
+    navigation_depth=4,
     path_to_docs="doc",
     use_edit_page_button=True,
     use_repository_button=True,