Revert "subtree updates"

Needs to go through CI

This reverts commit fc7e7973f3119e2bad511209aa336537dc5ffbed.
diff --git a/meta-raspberrypi/docs/conf.py b/meta-raspberrypi/docs/conf.py
index 39e7223..e7a2491 100644
--- a/meta-raspberrypi/docs/conf.py
+++ b/meta-raspberrypi/docs/conf.py
@@ -30,10 +30,7 @@
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = [
-    'myst_parser',
-    'sphinx_rtd_theme'
-]
+extensions = ['myst_parser']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -124,7 +121,6 @@
 # a list of builtin themes.
 #
 # html_theme = 'alabaster'
-html_theme = "sphinx_rtd_theme"
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the