readthedocs: use poetry to install dependencies

.readthedocs.yml

@@ -7,9 +7,21 @@ version: 2
 
 # Set the version of Python and other tools you might need
 build:
-  os: ubuntu-22.04
+  os: ubuntu-24.04
   tools:
-    python: "3.9"
+    python: "3.12"
+  jobs:
+    post_create_environment:
+      # Install poetry
+      # https://python-poetry.org/docs/#installing-manually
+      - pip install poetry
+    post_install:
+      # Install dependencies with 'docs' dependency group
+      # https://python-poetry.org/docs/managing-dependencies/#dependency-groups
+      # VIRTUAL_ENV needs to be set manually for now.
+      # See https://github.com/readthedocs/readthedocs.org/pull/11152/
+      - VIRTUAL_ENV=$READTHEDOCS_VIRTUALENV_PATH poetry install --only docs
+
 
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
@@ -18,8 +30,3 @@ sphinx:
 # If using Sphinx, optionally build your docs in additional formats such as PDF
 formats:
    - pdf
-
-# Optionally declare the Python requirements required to build your docs
-python:
-   install:
-   - requirements: docs/requirements.txt

pyproject.toml

@@ -42,6 +42,7 @@ dbus-fast = { version = ">=1.83.0, < 3", markers = "platform_system == 'Linux'"
 [tool.poetry.group.docs.dependencies]
 Sphinx = "^5.1.1"
 sphinx-rtd-theme = "^1.0.0"
+tomli = "^2.0.1"
 
 [tool.poetry.group.lint.dependencies]
 black = ">=24.3,<25.0"