fix: set navigation_with_keys value

False was the default value for navigation_with_keys. However, in version 0.14.2 of pydata-sphinx-theme, this default was removed and a warning was added that would be emitted whenever navigation_with_keys was not set. Because of the "SPHINXOPTS = -W" configuration in tox.ini, all warnings are promoted to an error. Therefore, it's necesary to set this value. I have set it to the default value explicitly.

Please see the following GitHub comments for context.
* pydata/pydata-sphinx-theme#1539
* pydata/pydata-sphinx-theme#987 (comment)

.readthedocs.yaml

@@ -5,12 +5,17 @@
 # Required: the version of this file's schema.
 version: 2
 
+build:
+   os: "ubuntu-20.04"
+   tools:
+      python: "3.8"
+
 # Build documentation in the docs/ directory with Sphinx
 sphinx:
    configuration: docs/api/source/conf.py
 
-# Optionally set the version of Python and requirements required to build your docs
+# We recommend specifying your dependencies to enable reproducible builds:
+# https://docs.readthedocs.io/en/stable/guides/reproducible-builds.html
 python:
-   version: "3.8"
    install:
    - requirements: requirements/doc.txt

docs/api/source/conf.py

@@ -60,6 +60,13 @@
  "use_repository_button": True,
  "use_issues_button": True,
  "use_edit_page_button": True,
+ # False was the default value for navigation_with_keys. However, in version 0.14.2 of pydata-sphinx-theme, this default
+ # was removed and a warning was added that would be emitted whenever navigation_with_keys was not set. Because of the
+ # "SPHINXOPTS = -W" configuration in tox.ini, all warnings are promoted to an error. Therefore, it's necesary to set
+ # this value. I have set it to the default value explicitly. Please see the following GitHub comments for context.
+ # https://github.com/pydata/pydata-sphinx-theme/issues/1539
+ # https://github.com/pydata/pydata-sphinx-theme/issues/987#issuecomment-1277214209
+ "navigation_with_keys": False,
  # Please don't change unless you know what you're doing.
  "extra_footer": """
         <a rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/">