update documentation building and drop version pinning

Author: xflr6

.readthedocs.yml

@@ -1,9 +1,9 @@
 # https://docs.readthedocs.io/en/stable/config-file/v2.html
 version: 2
 build:
-  os: ubuntu-20.04
+  os: ubuntu-lts-latest
   tools:
-    python: "3"
+    python: latest
 python:
   install:
     - method: pip

docs/conf.py

@@ -9,9 +9,9 @@
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-#
 import os
 import sys
+
 sys.path.insert(0, os.path.abspath(os.pardir))
 import bitsets
 
@@ -54,12 +54,10 @@
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-#
 on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
 if not on_rtd:
     import sphinx_rtd_theme
     html_theme = 'sphinx_rtd_theme'
-    html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,

pyproject.toml

@@ -30,7 +30,7 @@ Coverage = "https://codecov.io/gh/xflr6/bitsets"
 [project.optional-dependencies]
 dev = ["build", "wheel", "twine", "flake8", "Flake8-pyproject", "pep8-naming", "tox>=3"]
 test = ["pytest>=7", "pytest-cov"]
-docs = ["sphinx>=5", "sphinx-rtd-theme"]
+docs = ["sphinx", "sphinx-rtd-theme", "sphinx-rtd-theme"]
 visualization = ["graphviz~=0.7"]
 
 [build-system]